I need help simplifying this fraction...?

Question

The equation is as follows:

b(to the second)-25/b(to the second)-12b+35

Now the answer in the back of the book says that it should be (b+5)/(b-7) However, whenever I try doing the problem, I get -5/-12b+7.

What am I doing wrong, and how should I be doing the equation?

Answer 1

b(to the second)-25/b(to the second)-12b+35

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

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b^2 -12b+35 = (b-7)(b-5)

so the b-5 simplifies top and bottom

so u are left with  (b+5)/(b-7)  

Answer 2

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

b^2-12b+35= (b-7)(b-5)

therefore (b+5)(b-5)/(b-7)(b-5)

simplify and remove the (b-5)

that will leave you with (b+5)/(b-7)

you should not just be adding and subtracting you should first break it down so that you dont have any b^2 anywhere