2x + 3 + 5x = 10x - 31
This is a linear equation
The first thing to do is to collect the like terms
2x + 5x + 3 = 10x - 31
7x + 3 = 10x - 31
Re - arrange the equation base on it identity
7x - 10x = -31 - 3
-3x = -34
Divide both sides by -3
-3x / -3 = -34/-3
x = 34 / 3
3 can divide 34 in 11 times with a remainder of 1
Therefore, x = 11 1/3
The answer is 11 1/3