So my first question to you is, is this going to be a good case for u substitution? Well, when you look here, we, maybe the natural thing to set to be equal to u is seven x plus nine, but do I see its derivative anywhere over here? Well, let's see. If I set u to be equal to seven x plus nine, what is the derivative of u with respect to x going to be? Derivative of u with respect to x is just going to be equal to seven. Derivative of seven x is seven, derivative of nine is zero. So do we see a seven lying around anywhere over here?