# Math Help - Rational Expressions

1. ## Rational Expressions

What do i do next?

2. ## Re: Rational Expressions

Originally Posted by asilvester635
What do i do next?
Now start canceling common factors. Note that 4 -x = -(x - 4).

-Dan

3. ## Re: Rational Expressions

Originally Posted by asilvester635
What do i do next?
First of all, \displaystyle \begin{align*} 4 - x = (2 - x)(2 + x) \end{align*}, NOT \displaystyle \begin{align*} (x - 4)(x + 2) \end{align*}...

4. ## Re: Rational Expressions

I did the reciprocal to change the division into multiplication