Subtracting Rational Expressions: (a^2-2a-3)/(a^2-9a+18) -

[Softballgrl]

Someone help! I've been staring at this problem for an hour and a half

(a^2-2a-3)over(a^2-9a+18) - (a^2-5a-6)over(a^2+9a+8)

 

[wjm11]

Re: Subtracting Rational Expressions

Someone help! I've been staring at this problem for an hour and a half


(a^2-2a-3)over(a^2-9a+18) - (a^2-5a-6)over(a^2+9a+8)

Softballgrl,

1) Factor the quadratic trinomials in the denominators. For example, (a^2-9a+18) = (a - 3)(a - 6).

2) Find/Create a common denominator for the two fractions.

3) Combine the two fractions into one.

4) Combine terms in the numerator and simplify.

5) Factor the numerator if possible.

6) Cancel common factors in the numerator and denominator.