What x value makes this equation true ? x-3 = 3x + 7

So what you want to do is move all the variables to one side and numbers to the other.

x-3 = 3x + 7

So first move all the variables to one side:

x - 3x - 3 = 7

Then the numbers.

x- 3x = 7 + 3

Simplify

-2x = 10

Then divide both sides by -2.

-2x = 10

/-2     /-2

x = -5

The answer would be -3.9> -4.5