# How do you solve 10 + 4x =31 + x?

Sep 13, 2015

x=7

#### Explanation:

10+4x=31+x
10+4x+(-x)=31+x+(-x)
10+3x=31
(-10)+10+3x=31+(-10)
3x=21
x=7

x = 7

#### Explanation:

10 + 4x = 31 + x

Decide the side of the equation where variable terms (contain x) will stay.

Ex: variable terms will stay on the LEFT side of the equation.

Substract on BOTH sides of the equation the constants and variable terms you want to get rid of.

Ex: Get rid of 10 on the LEFT side of the equation, then substract 10 on BOTH sides.

Ex: Get rid of x on RIGHT side of the equation, then substract x on BOTH sides.

10-10 + 4x-x = 31-10 + x-x

4x-x = 31-10

then variables terms will be on ONLY one side of the equation and constants will be on the OTHER side of the equation

3x = 21

Divide BOTH sides of the equation by the value that multiplies x.

Ex: 3 multiplies x, then divide BOTH sides of the equation by 3.

3x÷3 = 21÷3

there is the answer: x = 7