How do you simplify (5b^2-125)/(20b^2-20)*(80b+80)/(4b-20)?

1 Answer
Jan 6, 2017

(5(b+5))/(b-1)

Explanation:

First, you can factorize all polynomials:

5b^2-125=5(b^2-25)=5(b-5)(b+5)

20b^2-20=20(b^2-1)=20(b-1)(b+1)

80b+80=80(b+1)

4b-20=4(b-5)

Then put them in the given expression:

(5cancel((b-5))(b+5))/(cancel20(b-1)cancel((b+1)))*(cancel80cancel((b+1)))/(cancel4cancel((b-5)))

(5(b+5))/(b-1)