I'm having trouble getting the correct answer when using the product rule to find a derivative.

For example when using the product rule to solve ((3x+1)^(3/2))*(2x+4)

I end up with the answer 9x^(3/2)+18x^(1/2)+6x^(3/2)+2^(3/2)

however my textbook says the answer is (5(3x+1)^(1/2))*(3x+4)

how do I get the answer in this form???

thanks to everyone in advance