2h-8=h+17

Here's what you need to do in order to solve for "h."

First, you need to get all the h's on one side of the equation.  To do that, you get rid of the h from the right side of the equation.  That is done by subtracting h (and you have to do it to both sides of the equation).

So that gives you (2h-h)-8=(h-h) + 17  which comes out to

h-8 = 17

So now to solve for h, you have to get all the numbers on the right side of the equation.  To do that, you add 8 to both sides (so that there is no longer a number on the left).

That gives you h = 17+8

So h = 25