Chapter 7 - Algebraic Fractions - 7.4 - Addition and Subtraction of Algebraic Fractions and Simplifying Complex Fractions - Problem Set 7.4 - Page 301: 72

The answer is below.

For the first fraction, you should use the second technique where you multiply the entire fraction by the least common multiple, for the denominators have a least common multiple of 12, which is fairly small and thus makes it fairly easy to simplify after doing this. For the second fraction, however, you should use the first technique where you simplify the fractions separately and then use division, for the least common multiple of the denominators given is fairly large. (This means that using the second technique with the least common multiple would be fairly complicated.)