Question

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

Find AB

Answer 1

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

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

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

= ` [(2 - 8, 6 + 20), (3 - 4, 9 + 10)] `

= `[(-6, 26), (-1, 19)]`