Question

If `((2, 3),(5, 7))((1, -3),(-2, 4)) = ((-4, 6),(-9, x))`, find x.

Answer 1

Given:

`((2, 3),(5, 7))((1, -3),(-2, 4)) = ((-4, 6),(-9, x))`

⇒ `((2 xx 1 + 3 xx (-2), 2 xx (-3) + 3 xx 4),(5 xx 1 + 7 xx (-2), 5 xx (-3) + 7 xx 4)) = ((-4, 6),(-9, x))`

⇒ `((-4, 6),(-9, 13)) = ((-4, 6),(-9, x))`

∴ x = 13