Question

 If A = `[(3, 1),(-1, 2)], B = [(1, 0),(0, 2)]`, find BA.

Answer 1

A = `[(3, 1),(-1, 2)], B = [(1, 0),(0, 2)]`

BA = `[(1, 0),(0, 2)] [(3, 1),(-1, 2)]`

= `[(1 xx 3 + 0 xx (-1), 1 xx 1 + 0 xx 2),(0 xx 3 + 2 xx (-1), 0 xx 1 + 2 xx 2)]`

= `[(3, 1),(-2, 4)]`