A garden has four sides that are all the same length. Each side measures x+4 units. The garden's perimeter is 112 units. What is the value of x?

The answer is 24. I figured this out by doing 112-16, because that way I won't have to figure it out with the + 4 each time. Then I just decided my answer (which was 96) by four, which is 24. And it checks out, because (24+4) * 4=112