We're going to do AU sub in this problem. So let U equal X / 3 minus lane two. So DU equals 1/3 DX or three DU equal DX. So now we get the integral of 5 * 3 or 15 hyperbolic sine of U DU. We know that that's just 15 hyperbolic cosine of U + C, So this is going to be 15 hyperbolic cosine of the X / 3 minus lane 2 + C.