# How do you solve the system of equations #x= - 4# and #- 8x - 5y = - 18# by using substitution?

##### 1 Answer

Mar 14, 2017

#### Answer:

Y is equal to 10. For how, see the explanation.

#### Explanation:

Substitute

This gets you:

Multiply

Subtract 32 from both sides:

Divide both sides by negative five:

You don't need to find x, since it's already given.

There are other ways to solve this with substitution, involving adding or subtracting different things in a different order, but they all end up with the same answer.