How to Evaluate fractions containing variables

This video is a great one on learning about evaluating fractions. The voice explains how to first plug in the numbers given for each variable in the fractions. He also explains the importance of simplifying the top and bottom first before simplifying the entire fraction. He also explains ways that would not be helpful in solving the problem and comparing that with the correct way. Then he notes the use of your simple math rules to find the answer. Excellent video for viewers.