6x-12 = 2x-6
get like terms on the same side by adding/subtracting.
6x - 12 = 2x - 6
+ 12, -2x on both sides
6x - 2x = -6 + 12
4x = 6
divide all by 4
x = 1.5
to check your answer, plug in 1.5 for x and see if they are equal to one another.
6(1.5) - 12 = -3
2(1.5) - 6 = -3