Question

find (AB)–1 , A–1B–1, and B1A–1. What do you observe?

Answer 1

matrix A: {left side: 2&1 Right side: -9&-4}
Matrix B: {right side:-9 &-4}

Answer 2

Matrix A: {left side;2&1, right side; -9&-4}
Matrix B: {left side; 9&7, right side 5&4}