Question

How do you solve `y=x-4` and `y=2x` using substitution?

Answer 1

`x=-4`
`y=-8`

Explanation:

`y=x-4`
`y=2x`

We know that `y` is `2x` so we replace `y` in the first equation with `2x`.

`2x=x-4`
`2x-x=-4`
`x=-4`

If `y` is `2x`, then `y`=(-4)x2= -8.

`x=-4`
`y=-8`