Question

Let `A = [(2, 4),(3, 2)], B = [(1, 3),(-2, 5)], C = [(-2, 5),(3, 4)]`

Find BA

Answer 1

Matrix B has 2 columns. This number is equal to the number of rows in matrix A. Therefore, BA is defined as:

`BA = [(1, 3),(-2, 5)][(2, 4),(3, 2)]`

= `[(1(2) + 3(3), 1(4) + 3(2)), (-2(2) + 5(3), -2(4) + 5(2))]`

= `[(2 + 9, 4 + 6), (-4 + 15, -8 + 10)]`

= `[(11, 10),(11, 2)]`