Substitute in what you already know into the formula, since the formula is (a=bh) you already know what A is so now you have 50=bh, now the length is x+7 , length is basically height , so h in the formula , so now you get 50=b(x+7) , now you need b luckily you already have b, so plug in 50=(x+2)(x+7) , you can guess and check or you can solve for x by double distributing
