a 13 points Find a 4 x 4 matrix C such that i C is not

Last updated: 4/24/2023

a 13 points Find a 4 x 4 matrix C such that i C is not invertible and ii every entry of C is nonzero b 12 points Does there exist a 5x2 matrix A and a 2x5 matrix B such that AB is invert Either provide a 5x2 matrix A and a 2x5 matrix B such that AB is invertible or other show that for every 5x2 matrix A and every 2x5 matrix B the product AB is not invert