1. 7.4: Add and subtract rational exp.
What do we have to have in order to add or subtract fractions? _______________________
So, if we want to add we would get ______.
ALL fraction answers need to be in simplest form!
This applies to our rational expressions too 

2. EX:
What are the domain restriction(s)? __________
Add, then simplify!

3. 3/1 Simpify, leave only positive exponents: 1)
Add or subtract, make sure your answer is in simplest form:
2) )

4. What about NON-common denominators?
What is the common denominator? _________
So, our new answer will be ______________

5. So now, with rational expressions….
We need common denominators for rational expressions too.
ALWAYS factor the denominators first. We don’t want to factor the numerators!

6. Class practice