Complex numbers Questions and Answers

Question 29 Reciprocal of 1 is 1 Reciprocal of 2 is 5 8 Reciprocal of 0 is Submit Question
Algebra
Complex numbers
Question 29 Reciprocal of 1 is 1 Reciprocal of 2 is 5 8 Reciprocal of 0 is Submit Question
1 3 9 5 Give your answer as a fraction reduced to lowest terms Multiply
Algebra
Complex numbers
1 3 9 5 Give your answer as a fraction reduced to lowest terms Multiply
Larry and Peggy are making decisions about their bank accounts Larry wants to deposit 350 as a principal amount with an interest of 4 compounded quarterly Peggy wants to deposit 350 as the principal amount with an interest of 6 compounded monthly Explain which method results in more money after 2 years Show all work
Algebra
Complex numbers
Larry and Peggy are making decisions about their bank accounts Larry wants to deposit 350 as a principal amount with an interest of 4 compounded quarterly Peggy wants to deposit 350 as the principal amount with an interest of 6 compounded monthly Explain which method results in more money after 2 years Show all work
Add 28 782 5 188 16 542 1561 X
Algebra
Complex numbers
Add 28 782 5 188 16 542 1561 X
How would you say each of these inequalities The inequality y 7 would be read Select an answer The inequality y 7 would be read Select an answer C C How would you write each of these inequalities in symbolic form The inequality y is less than 7 would be written Select an answer The inequality y is less than or equal to 7 would be written Select an answer C
Algebra
Complex numbers
How would you say each of these inequalities The inequality y 7 would be read Select an answer The inequality y 7 would be read Select an answer C C How would you write each of these inequalities in symbolic form The inequality y is less than 7 would be written Select an answer The inequality y is less than or equal to 7 would be written Select an answer C
Subtract 21532 6086
Algebra
Complex numbers
Subtract 21532 6086
Multiply 454 116
Algebra
Complex numbers
Multiply 454 116
2 35 x3 52 x 5 x 5 x
Algebra
Complex numbers
2 35 x3 52 x 5 x 5 x
low 33 0 ft above the street the angle of elevation to the top of the building across the street is 46 0 and the angle of depression to the base of this building is 18 0 Find the height of the building across the street The height of the building across the street is 141 ft Round to the nearest whole number as needed Points 0 of 1 46 0 56 5 of 9 points 18 0
Algebra
Complex numbers
low 33 0 ft above the street the angle of elevation to the top of the building across the street is 46 0 and the angle of depression to the base of this building is 18 0 Find the height of the building across the street The height of the building across the street is 141 ft Round to the nearest whole number as needed Points 0 of 1 46 0 56 5 of 9 points 18 0
Find h as indicated in the figure h Round to the nearest integer as needed 28 5 335 4
Algebra
Complex numbers
Find h as indicated in the figure h Round to the nearest integer as needed 28 5 335 4
27 2x 3 4x
Algebra
Complex numbers
27 2x 3 4x
each side length 11 A polynomial function P x has degree n If n is even is the number of turning points of the graph of P x even or odd What can you say about the number of turning points if n is odd 5 2 Polynomials Linear Factors and Zeros gree of the polynomial that
Algebra
Complex numbers
each side length 11 A polynomial function P x has degree n If n is even is the number of turning points of the graph of P x even or odd What can you say about the number of turning points if n is odd 5 2 Polynomials Linear Factors and Zeros gree of the polynomial that
Time t Velocity a Find v 4 and explain what it means 02 4 6 8 0 32 48 61 73 b Find the average rate of change per second in the velocity from the time t 2 t the time t 4 Be sure to give the units
Algebra
Complex numbers
Time t Velocity a Find v 4 and explain what it means 02 4 6 8 0 32 48 61 73 b Find the average rate of change per second in the velocity from the time t 2 t the time t 4 Be sure to give the units
Factor the polynomial f x Then solve the equation f x 0 f x x 6x 3x 10 The factored form is f x
Algebra
Complex numbers
Factor the polynomial f x Then solve the equation f x 0 f x x 6x 3x 10 The factored form is f x
Use long division to find the quotient Q x and the remainder R x when P x is divided by d x and express P x in the form d x Q x R x 4 2 P x x 6x 28 d x x 3 P x x 3
Algebra
Complex numbers
Use long division to find the quotient Q x and the remainder R x when P x is divided by d x and express P x in the form d x Q x R x 4 2 P x x 6x 28 d x x 3 P x x 3
Factor the polynomial function f x Then solve the equation f x 0 3 f x x 12x 29x 42 The factored polynomial function is f x Factor completely
Algebra
Complex numbers
Factor the polynomial function f x Then solve the equation f x 0 3 f x x 12x 29x 42 The factored polynomial function is f x Factor completely
g 1 j 2 8 4 7 9 8 n 1 n n 1 n n 1 n 2 n 1 n h i k n 2 n 1 n 2 n 1 n 1 n 2n 1 2n 2 2n 2n 1
Algebra
Complex numbers
g 1 j 2 8 4 7 9 8 n 1 n n 1 n n 1 n 2 n 1 n h i k n 2 n 1 n 2 n 1 n 1 n 2n 1 2n 2 2n 2n 1
Find the equation of the line with same x intercepts and y intercepts x y 4x 4y 4 0 as the circle
Algebra
Complex numbers
Find the equation of the line with same x intercepts and y intercepts x y 4x 4y 4 0 as the circle
Find the equation of the line through 1 4 and perpendicular to 5x 2y 14
Algebra
Complex numbers
Find the equation of the line through 1 4 and perpendicular to 5x 2y 14
Show that the slope of the line passing through x x and x h x h can be expressed as
Algebra
Complex numbers
Show that the slope of the line passing through x x and x h x h can be expressed as
Find the equation of the line through 2 1 and parallel to the x axis
Algebra
Complex numbers
Find the equation of the line through 2 1 and parallel to the x axis
2 Find the equation the line through the points 2 3 and 3 5 Write the answer in the form Ax By C 0
Algebra
Complex numbers
2 Find the equation the line through the points 2 3 and 3 5 Write the answer in the form Ax By C 0
Graph the following system of inequalities on your own graph paper Use your graph to answer the following questions x y 21 This line should be x 2y 4 This line should be The lines intersect at the point The solution region is the intersection point
Algebra
Complex numbers
Graph the following system of inequalities on your own graph paper Use your graph to answer the following questions x y 21 This line should be x 2y 4 This line should be The lines intersect at the point The solution region is the intersection point
Tools Write and solve a word problem that is modeled with the number line 0 77 78 10 20 30 40 50 28 35 SE YOU
Algebra
Complex numbers
Tools Write and solve a word problem that is modeled with the number line 0 77 78 10 20 30 40 50 28 35 SE YOU
Find the equation of the line with the given properties Write the equation in slope intercept form Graph the line containing X Y 10 1 m 25 The equation of the line is y X 3 Type your answer in slope intercept form Use integers or fractions for any numbers in the equation Use the graphing tool to graph the line Click to enlarge graph 2 5 Points 0 5 of 1 10 10
Algebra
Complex numbers
Find the equation of the line with the given properties Write the equation in slope intercept form Graph the line containing X Y 10 1 m 25 The equation of the line is y X 3 Type your answer in slope intercept form Use integers or fractions for any numbers in the equation Use the graphing tool to graph the line Click to enlarge graph 2 5 Points 0 5 of 1 10 10
2 Graph the function f x x 8x 11 by starting with the graph of y x and using transformations shifting stretching compressing and or reflecting Select all the transformations needed to graph the given function using y x 2 A Compress the graph vertically by a factor of 5 B Shift the graph up 5 units C Reflect the graph about the y axis D Shift the graph down 5 units E Shift the graph to the right 4 units F Reflect the graph about the x axis G Stretch the graph vertically by a factor of 8
Algebra
Complex numbers
2 Graph the function f x x 8x 11 by starting with the graph of y x and using transformations shifting stretching compressing and or reflecting Select all the transformations needed to graph the given function using y x 2 A Compress the graph vertically by a factor of 5 B Shift the graph up 5 units C Reflect the graph about the y axis D Shift the graph down 5 units E Shift the graph to the right 4 units F Reflect the graph about the x axis G Stretch the graph vertically by a factor of 8
2 4 pts Match the following correlation coefficients in the box to the right with their corresponding scatterplots below css linear r 0 6 r more linear r 0 8 r 0 8 0 6 r 0 r 0 9
Algebra
Complex numbers
2 4 pts Match the following correlation coefficients in the box to the right with their corresponding scatterplots below css linear r 0 6 r more linear r 0 8 r 0 8 0 6 r 0 r 0 9
2 4 pts Match the following correlation coefficients in the box to the right with their corresponding scatterplots below r r r 0 8 r 0 6 r 0 r 0 9
Algebra
Complex numbers
2 4 pts Match the following correlation coefficients in the box to the right with their corresponding scatterplots below r r r 0 8 r 0 6 r 0 r 0 9
Make a scatter plot for the given data Use the scatter plot to describe whether or not the variables appear to be related 9 7 2 6 5 11 8 9 x y 12 4 0 3 6 12 O A 22 TTTTT 10 X TE 21 The variables appear to be related O B A 10 Ay 22 X 21 The variables do not appear to be related O C T 10 22 X 21 The variables appear to be related O D 10 Ay 22 9 21 The variables appear to be related
Algebra
Complex numbers
Make a scatter plot for the given data Use the scatter plot to describe whether or not the variables appear to be related 9 7 2 6 5 11 8 9 x y 12 4 0 3 6 12 O A 22 TTTTT 10 X TE 21 The variables appear to be related O B A 10 Ay 22 X 21 The variables do not appear to be related O C T 10 22 X 21 The variables appear to be related O D 10 Ay 22 9 21 The variables appear to be related
This question 1 point s possible First create a scatter plot for the data in the table Then use the shape of the scatter plot given to determine if the data are best modeled by a linear function an exponential function a logarithmic function or a quadratic function OA Ay 5 X T 6 0 logarithmic function OB Ay 5 X 6 quadratic function O C 0 6 exponential function O D Ay 5 linear function Q Q Submit quiz X y 0 05 4 1 0 4 3 12 2 1 3 5 0 2 4 0 15 5 0 1
Algebra
Complex numbers
This question 1 point s possible First create a scatter plot for the data in the table Then use the shape of the scatter plot given to determine if the data are best modeled by a linear function an exponential function a logarithmic function or a quadratic function OA Ay 5 X T 6 0 logarithmic function OB Ay 5 X 6 quadratic function O C 0 6 exponential function O D Ay 5 linear function Q Q Submit quiz X y 0 05 4 1 0 4 3 12 2 1 3 5 0 2 4 0 15 5 0 1
Solve f x g x What are the points of intersection of the graphs of the two functions g x 4 2 f x x 6x 4 The x values in the solution set of f x g x are 0 6 Use a comma to separate answers as needed What are the points of intersection of the graphs of the two functions Select the corre if necessary fill in the answer box within your choice O A The graphs of the two functions intersect at the point s Simplify your answer Type an ordered pair Use a comma to separate answer fractions for any numbers in the expression O B The graphs of the two functions do not intersect
Algebra
Complex numbers
Solve f x g x What are the points of intersection of the graphs of the two functions g x 4 2 f x x 6x 4 The x values in the solution set of f x g x are 0 6 Use a comma to separate answers as needed What are the points of intersection of the graphs of the two functions Select the corre if necessary fill in the answer box within your choice O A The graphs of the two functions intersect at the point s Simplify your answer Type an ordered pair Use a comma to separate answer fractions for any numbers in the expression O B The graphs of the two functions do not intersect
Suppose that f x x 5x 36 and g x x 3x 18 a Find the zeros of f g x b Find the zeros of f g x c Find the zeros of f g x a What are the zeros of f g x
Algebra
Complex numbers
Suppose that f x x 5x 36 and g x x 3x 18 a Find the zeros of f g x b Find the zeros of f g x c Find the zeros of f g x a What are the zeros of f g x
Use the graphs below to choose the correct symbol from each dropdown menu h x 5 g x 4 5 4 3 2 10 1 3 2 1 b h 0 1 2 3 4 5 4 3 2 1 3 2 1 O 1 2 3 A g 0 1 10 3 4 5 2 X F3 4 X a The number of values for x where h x 0 The number of values for x where g x 0 75
Algebra
Complex numbers
Use the graphs below to choose the correct symbol from each dropdown menu h x 5 g x 4 5 4 3 2 10 1 3 2 1 b h 0 1 2 3 4 5 4 3 2 1 3 2 1 O 1 2 3 A g 0 1 10 3 4 5 2 X F3 4 X a The number of values for x where h x 0 The number of values for x where g x 0 75
Solve f x g x What are the points of intersection of the graphs of the two functions 2 f x x x 1 g x 2x 3x 62 f f x g x then x
Algebra
Complex numbers
Solve f x g x What are the points of intersection of the graphs of the two functions 2 f x x x 1 g x 2x 3x 62 f f x g x then x
Annual high temperatures in a certain location have been tracked for several years Let X represent the year and Y the high temperature Based on the data shown below calculate the regression line each value to two decimal places y 03 X y 5 17 78 6 18 86 7 16 44 8 17 32 9 18 4 10 17 08 11 16 26 12 16 94 13 16 92 Xx 20 25 X
Algebra
Complex numbers
Annual high temperatures in a certain location have been tracked for several years Let X represent the year and Y the high temperature Based on the data shown below calculate the regression line each value to two decimal places y 03 X y 5 17 78 6 18 86 7 16 44 8 17 32 9 18 4 10 17 08 11 16 26 12 16 94 13 16 92 Xx 20 25 X
A 10 5 m fire truck ladder is leaning against a wall Find the distance d the ladder goes up the wall above the fire truck if the ladder makes an angle of 41 24 with the horizontal 10 5 m d 4 41 24 d 6 92 m Simplify your answer Type an integer or a decimal Round to the nearest hundredth
Algebra
Complex numbers
A 10 5 m fire truck ladder is leaning against a wall Find the distance d the ladder goes up the wall above the fire truck if the ladder makes an angle of 41 24 with the horizontal 10 5 m d 4 41 24 d 6 92 m Simplify your answer Type an integer or a decimal Round to the nearest hundredth
Use the following graph to choose the correct responses from each dropdown menu below a f 2 f x c For LO 4 3 2 1 4 3 2 1 0 1 2 1 2 b When f x 0 the value of x is values of x f x 1 3 4
Algebra
Complex numbers
Use the following graph to choose the correct responses from each dropdown menu below a f 2 f x c For LO 4 3 2 1 4 3 2 1 0 1 2 1 2 b When f x 0 the value of x is values of x f x 1 3 4
What are the roots of the polynomial equation 0 x 26x 48 Select each correct answer 0 24 0 0 0 0 2 02
Algebra
Complex numbers
What are the roots of the polynomial equation 0 x 26x 48 Select each correct answer 0 24 0 0 0 0 2 02
What are the solutions to the equation 4x X 36x Enter your answers in the boxes or x or x
Algebra
Complex numbers
What are the solutions to the equation 4x X 36x Enter your answers in the boxes or x or x
A 10 5 m fire truck ladder is leaning against a wall Find the distance d the ladder goes up the wall above the fire truck if the ladder makes an angle of 41 24 with the horizontal 10 5 m 41 24 Points 0 of 1 Save dem Simplify your answer Type an integer or a decimal Round to the nearest hundredth
Algebra
Complex numbers
A 10 5 m fire truck ladder is leaning against a wall Find the distance d the ladder goes up the wall above the fire truck if the ladder makes an angle of 41 24 with the horizontal 10 5 m 41 24 Points 0 of 1 Save dem Simplify your answer Type an integer or a decimal Round to the nearest hundredth
Wat is the meaning of the term angle of elevation OA If B is a point above point A as shown in the figure then the angle of elevation from A to B is the obtuse angle formed by the horizontal line through A and the line of sight from A to B Angle of elevation Horizontal A B O C If B is a point above point A as shown in the figure then the angle of elevation from A to B is the acute angle formed by the vertical line through A and the line of sight from A to B Vertical Angle of elevation Q Q G M B If B is a point above point A as shown in the fig then the angle of elevation from A to B is the acu angle formed by the horizontal line through A and line of sight from A to B B Angle of elevation Horizontal D If B is a point above point A as shown in the figure then the angle of elevation from A to B is the acute angle formed by the horizontal line through B and the line of sight from A to B Horizontal Angle of elevation B
Algebra
Complex numbers
Wat is the meaning of the term angle of elevation OA If B is a point above point A as shown in the figure then the angle of elevation from A to B is the obtuse angle formed by the horizontal line through A and the line of sight from A to B Angle of elevation Horizontal A B O C If B is a point above point A as shown in the figure then the angle of elevation from A to B is the acute angle formed by the vertical line through A and the line of sight from A to B Vertical Angle of elevation Q Q G M B If B is a point above point A as shown in the fig then the angle of elevation from A to B is the acu angle formed by the horizontal line through A and line of sight from A to B B Angle of elevation Horizontal D If B is a point above point A as shown in the figure then the angle of elevation from A to B is the acute angle formed by the horizontal line through B and the line of sight from A to B Horizontal Angle of elevation B
Solve the right triangle ABC with C 90 A 35 6 b 34 7 cm B a C www Simplify your answer Type an integer or a decimal Round to the nearest tenth as needed cm Simplify your answer Type an integer or a decimal Round to the nearest tenth as needed cm Simplify your answer Type an integer or a decimal Round to the nearest tenth as needed
Algebra
Complex numbers
Solve the right triangle ABC with C 90 A 35 6 b 34 7 cm B a C www Simplify your answer Type an integer or a decimal Round to the nearest tenth as needed cm Simplify your answer Type an integer or a decimal Round to the nearest tenth as needed cm Simplify your answer Type an integer or a decimal Round to the nearest tenth as needed
Evaluating and Solving an Equation Application Identify the information given to you in the application problem below Use that information to answer the questions that follow Round your answers to two decimal places as needed Hampton is a door to door vacuum salesman His weekly salary S v is given by the linear function S v 400 120v where v is the number of vacuums sold Identify the slope and complete the following sentence to explain the meaning of the slope Hampton earns 120 Find the Vertical Intercept Complete the following sentence to explain the meaning of the Vertical Intercept If Hampton sells 400 per vacuum sold x vacuums he will still earns a base salary of
Algebra
Complex numbers
Evaluating and Solving an Equation Application Identify the information given to you in the application problem below Use that information to answer the questions that follow Round your answers to two decimal places as needed Hampton is a door to door vacuum salesman His weekly salary S v is given by the linear function S v 400 120v where v is the number of vacuums sold Identify the slope and complete the following sentence to explain the meaning of the slope Hampton earns 120 Find the Vertical Intercept Complete the following sentence to explain the meaning of the Vertical Intercept If Hampton sells 400 per vacuum sold x vacuums he will still earns a base salary of
Find the equation of the line with the given properties Write the equation in slope intercept form Graph the line m 2 containing x x 4 5 The equation of the line is Type your answer in slope intercept form Use integers or fractions for any numbers in the equation
Algebra
Complex numbers
Find the equation of the line with the given properties Write the equation in slope intercept form Graph the line m 2 containing x x 4 5 The equation of the line is Type your answer in slope intercept form Use integers or fractions for any numbers in the equation
The point slope form of a nonvertical line that has a slope of m and contains the point X is y y m x x x x m y Y
Algebra
Complex numbers
The point slope form of a nonvertical line that has a slope of m and contains the point X is y y m x x x x m y Y
In the figure shows the relationship between the percentage of married females of child bearing age using contraceptives and births per female in selected countries Use the sca plot to determine whether there is a strong negative correlation between contraceptive use and births per female Click the icon to view a scatter plot of contraceptive prevalence and average births per female There is a strong negative correlation between contraceptive use and births per female O False O True Scatter Plot of Contraceptive Prevalence vs Births per Female Births per Female 5987654321 10 0 0 Contraceptive Prevalence and Average Number of Births per Female Selected Countries Kenya Syria Jordan Botswana Zimbabwe Lesotho 10 Vietnam Honduras Fiji Chile CLUB M Costa Rica Spain Denmark 20 30 40 50 60 Percentage of Married Females of Child Bearing Age Using Contraceptives 70 80 X
Algebra
Complex numbers
In the figure shows the relationship between the percentage of married females of child bearing age using contraceptives and births per female in selected countries Use the sca plot to determine whether there is a strong negative correlation between contraceptive use and births per female Click the icon to view a scatter plot of contraceptive prevalence and average births per female There is a strong negative correlation between contraceptive use and births per female O False O True Scatter Plot of Contraceptive Prevalence vs Births per Female Births per Female 5987654321 10 0 0 Contraceptive Prevalence and Average Number of Births per Female Selected Countries Kenya Syria Jordan Botswana Zimbabwe Lesotho 10 Vietnam Honduras Fiji Chile CLUB M Costa Rica Spain Denmark 20 30 40 50 60 Percentage of Married Females of Child Bearing Age Using Contraceptives 70 80 X
The figure shows the graphs of the cost and revenue functions for a company that manufactures and sells external hard drives The solid line represents the revenue function R x 45x the dashed line represents the cost function C x 5000 20x Use the formulas to find R 350 C 350 Describe what this means for the company R 350 C 350 3750 Type an integer or a decimal Describe what this means for the company When the company produces and sells hard drives the for the company is Ints 0 25 of 1 OF LAMB 40 000 30 000 20 000 10 000 0 0 AY Rex x ext5000 20x 200 400 600 800 Hard Drives Produced and Sold Save Q G
Algebra
Complex numbers
The figure shows the graphs of the cost and revenue functions for a company that manufactures and sells external hard drives The solid line represents the revenue function R x 45x the dashed line represents the cost function C x 5000 20x Use the formulas to find R 350 C 350 Describe what this means for the company R 350 C 350 3750 Type an integer or a decimal Describe what this means for the company When the company produces and sells hard drives the for the company is Ints 0 25 of 1 OF LAMB 40 000 30 000 20 000 10 000 0 0 AY Rex x ext5000 20x 200 400 600 800 Hard Drives Produced and Sold Save Q G
O Points 0 of 1 The figure shows the graphs of the cost and revenue functions for a company that manufactures and sells external hard drives The solid line represents the revenue function R x 60x the dashed line represents the cost function C x 5000 35x Use the formulas to find R 150 C 150 Describe what this means for the company R 150 C 150 Type an integer or a decimal Part 1 of 2 40 000 30 000 20 000 10 000 of 0 0 AY RX 60x Cx 5000 5x 200 400 600 800 Hard Drives Produced and Sold Save O Gi
Algebra
Complex numbers
O Points 0 of 1 The figure shows the graphs of the cost and revenue functions for a company that manufactures and sells external hard drives The solid line represents the revenue function R x 60x the dashed line represents the cost function C x 5000 35x Use the formulas to find R 150 C 150 Describe what this means for the company R 150 C 150 Type an integer or a decimal Part 1 of 2 40 000 30 000 20 000 10 000 of 0 0 AY RX 60x Cx 5000 5x 200 400 600 800 Hard Drives Produced and Sold Save O Gi
F The figure shows the graphs of the cost and revenue functions for a company that manufactures and sells external hard drives The solid line represents the revenue function R x 60x the dashed line represents the cost function C x 15 000 25x a Use the formulas to write the company s profit function P from producing and selling x hard drives b Find the company s profit if 21 000 hard drives are produced and sold a The company s profit function is P x Simplify your answer Score 43 75 3 5 of 8 points Points 0 5 of 1 40 000 30 000 20 000 Ay 10 000 0 0 5 Rpx 637 Cix 15 800 25 Save 200 400 600 800 Hard Drives Produced and Sold Q Q 15
Algebra
Complex numbers
F The figure shows the graphs of the cost and revenue functions for a company that manufactures and sells external hard drives The solid line represents the revenue function R x 60x the dashed line represents the cost function C x 15 000 25x a Use the formulas to write the company s profit function P from producing and selling x hard drives b Find the company s profit if 21 000 hard drives are produced and sold a The company s profit function is P x Simplify your answer Score 43 75 3 5 of 8 points Points 0 5 of 1 40 000 30 000 20 000 Ay 10 000 0 0 5 Rpx 637 Cix 15 800 25 Save 200 400 600 800 Hard Drives Produced and Sold Q Q 15
9 Fill in the integer values of each square root on the number line 0 VI 10 5 Between 13 Between r line above to 4 ann and 9 Use the number line above to help determine the two positive integers each square roc between and 5 What two integers is 15 between Which integer is it closer to aproximate 15 to the nearest tenth 16 25 36 and 49 13 26 Between 11 59 Between and 20 64 and
Algebra
Complex numbers
9 Fill in the integer values of each square root on the number line 0 VI 10 5 Between 13 Between r line above to 4 ann and 9 Use the number line above to help determine the two positive integers each square roc between and 5 What two integers is 15 between Which integer is it closer to aproximate 15 to the nearest tenth 16 25 36 and 49 13 26 Between 11 59 Between and 20 64 and