# How do you solve #3x + y = 7# and #3x - y = 5#?

##### 1 Answer

#### Explanation:

There are 2 obvious methods which can be used in this example, based on the x and y values in the equations.

**ELIMINATION METHOD**

The two y terms are additive inverses. This means they have the same value, but opposite signs.

When they are ADDED together, they will make 0.

Substitute into A to find the value of y:

**EQUATING METHOD**

The two x-terms are exactly the same. Make the x term the subject.

But

Therefore

solve for y:

If