Question

how does one check the product of two rational expressions?

Answer 1

You can substitute the final solution you get and check if it = the question.

Answer 2

You can substitute the solutions into the original rational expressions and see if the solutions are correct. There is also a simple method of checking the product of two rational expressions would be to caste out nines. Here is an example:
http://www.themathlab.com/natural/mental … (hope this helps!)