Multiplying rational expressions is similar to dividing polynomials. All you have to do is factor and eliminate the terms. Here is an example to help you out :
X²+8x+15 (X+5) (X+3) ( X+3)
X²+10x+25 (X+5) (X+5) ( X+5)
If you are having any trouble look at the picture , it might help you out :




