So first you’ll get the variable on one side so you subtract 2x to x getting -x. That leaves you with 6=-x+15. Then you want to subtract 15 from 6 to get the variable alone. This makes -9=-x then you remove the subtraction symbols because they’re on both sides and if you divide x by -1 and -9 by -1 you get x=9 anyways. So that’s you’re answer x=9.
