Question

How do you solve `x + y = -4` and `y = -3x + 2` using substitution?

Answer 1

`x = 3` and `y = -7`

Explanation:

We already know that `y = -3x + 2`
So we must substitute `y`(in the equation) for `-3x + 2`
So...

`-3x + 2 + x = -4`
`-2x + 2 = -4`
`-2x = -6`
`2x = 6`
`x = 3`

So...

`3 + y = -4`
`y =-7`