how to add with unlike denominators

1. take the 2 (or more) fractions (2/9 and 5/7)
2. find the LCM (63, for this one)
3. make equivalent fractions (remember, what is done to the bottom must be done to the top
4. add (14/63+45/63)
5. change it to lowest terms (69/63=1 6/63=1 2/21)
6. you're done!