CPM Homework Help : A2C Problem 12-12

Find the sum.

$\frac { a } { b } + \frac { c } { d }$
Hint (a):
Find a common denominator.
Answer (a):
$\frac{ad+bc}{bd}$

$\frac { a } { b } + \frac { c } { d } + \frac { e } { f }$
Hint (b):
Find a common denominator. If you need to, combine them two at a time.