Question

How do you solve by substitution `2x-y=23` and `x-9=-1`?

Answer 1

We write the second equation `x= 9 -1 = 8` and substitute into the first: `2(8) - y = 23` or `y = 2(8)-23=-7`.

Explanation:

Check `x=8, y=-7`

`2(8) - (-7) = 16 + 7 = 23 quad sqrt`

`8 - 9 = -1 quad sqrt`