One thing that I learned while multiplying or dividing rational expressions is that I can flip a binomial to match another binomial so they can cancel eachother out and make the question easier to simplify.

Example:

if you have a binomial that could cancel out with another binomial if the signs were different then all you have to do is multiply it with -1 and you can flip the binomial and cancel it out. But remember to change the overall sign from + to – .