To solve 4x - 12 = 3x - 3, we must isolate the variable, x.
First, move all terms that contain the variable, x to one side, and all the constant terms to the other.
Let's move 3x to the other side. To do that, we can subtract 3x on both sides. This cancels out 3x on the right side since 3x - 3x equals 0.
4x - 12 - 3x = -3
Now, let's move -12 to -13. To do that, we can add 12 on both sides. -12 + 12 equals 0.
4x - 3x = -3 + 12
Now, combine the like terms.
x = 9
And that's it!