Question

How do you solve `2x+7y=15` and `x=3-2y` using substitution?

Answer 1

`y=3`

Explanation:

As `x=3-2y`, we can replace `x`in the other equation with this, turning it into

`2(3-2y)+7y=15` which when expanded

`6-4y+7y=15`

`6+3y=15`

`3y=9`

`y=3`