Simplifying and Rearranging Polynomial Expressions

[GeneralOJB]

Differentiate and simplify:
y=(x+1)(2x-3)$$^{4}$$

I got:
8(x+1)(2x-3)$$^{3}$$ + (2x-3)$$^{4}$$.

But the answers in the answer booklet say:
5(2x+1)(2x-3)$$^{3}$$

I put both answers in Wolfram Alpha and found they were both equal. So this is just a matter of simplifying/rearranging.

Could someone please explain to me how to simplify my answer to get the answer in the booklet? This one's annoying me as I just can't seem to do it.

 

[LCKurtz]

Factor out a (2x-3)³.

 

[GeneralOJB]

Thanks so much! I can't believe I never thought to do that.