Answer 1

`x[(-1), (2)] - 4[(-2), (y)] = [(7),(-8)]`

`[(-x),(2x)] - [(-8),(4y)] = [(7),(-8)]`

`[(-x + 8),(2x - 4y)] = [(7),(-8)]`

Comparing corresponding the elements we get

-x + 8 = 7 and 2x - 4y = -8

Simplifying we get

x = 1 and y = `5/2` = 2.5