Problem 1 notes:
The Least Common Denominator or LCD is 8. Multiply BOTH the top and bottom of the first fraction by 2 to create the common denominator.
Problem 2 notes:
The Least Common Demoninator is a(a-5). Notice that one of the denominators now contains a binomial, (a-5). Remember that the a in (a-5) cannot go anywhere without his buddy (-5) tagging along. You cannot separate the a from the -5, as they must com as a pair. In addition, you can never reduce (cancel) only the a or only the 5 in (a-5). The answer can be expressed in several different ways, but this is the one I prefer.
PROBLEM 1
PROBLEM 2
REFLECTION
I was very confused when we were doing these in class. I always messed up because I wouldn't leave enough room for my work and I wouldn't be able to find the LCD and multiply it to both sides. It was a mess. Now I understand how to add and subtract rational expressions!
ADDITIONAL RESOURCES
http://mcckc.edu/common/services/BR_Tutoring/files/math/functions/Adding_&_Subtracting_Rational_Expressions.pdf
