Question

Find matrix X, if `[(3, 7),(2, 4)] [(0, 2),(5, 3)] + x = [(1, -5),(-4, 6)]`

Answer 1

Compute the product A.B, where

A = `[(3, 7),(2, 4)]`

B = `[(0, 2),(5, 3)]`

A × B = `[(3, 7),(2, 4)] × [(0, 2),(5, 3)]`

= `[(3 xx 0 + 7 xx 5, 3 xx 2 + 7 xx 3),(2 xx 0 + 4 xx 5, 2 xx 2 + 4 xx 3)]`

= `[(0 + 35, 6 + 21),(0 + 20, 4 + 12)]`

= `[(35, 27),(20, 16)]`

Use the equation to solve for x

`[(35, 27),(20, 16)] + x = [(1, -5),(-4, 6)]`

`x = [(1 -35, -5 - 27),(-4 - 20, 6 - 16)]`

= `[(-34, -32),(-24, -10)]`