-3x + 18 = 7x - 12
we want to get x on only one side so you would add 3x to 7x
18 = 10x - 12
next, we want the 18 and 12 on the same side so you add 12 to 18
30 = 10x
finally we want the x by itself so you will divide 10x and 30 (since you need to do it for both sides) by 10
final answer:
10 = x
or
x = 10
