Our first step is to distribute -3 in (5+7x) for easier in solving the Inequality.
Move the x-terms to the same side and constant term as well.
Moving to another side, changing the operator/sign to opposite. (Basically from Plus to Minus and Multiply to Divide)
Then move -15 to divide 45. Remember, moving the negative coefficient as you have to change the sign/symbol/operator of Inequality.
Therefore, the answer is x < -3.