5a/6bc^2 + 3b/8a^2c. The LCM for this, as I worked it out, is 24a^2bc^3. The book say's it's 24a^2bc^2. And my simplification was: 20a^3 + 9b^2c^3/24a^2bc^3. The book's answer is 20a^3 + 9b^2c/24a^2bc^2. Why isn't the LCM c^3? And why is there only one "c" variable in the simplification (i.e. 20a^3 + 9b^2c). Why are the "c" variables being cancelled out while the "b" and "a" variables aren't?