# Question #af32b

Feb 2, 2017

You make them have the same denominators

#### Explanation:

If you have a fraction, you can multiply the top and the bottom by the same number and the fraction remains the same.

Ex: $\frac{4}{9} = \frac{4 \cdot 2}{9 \cdot 2} = \frac{8}{18}$

So you can make sure that the denominators are equal by finding the "least common multiple" and making that the denominator of both fractions.

Ex: $\frac{4}{9} + \frac{1}{6}$

The least common multiple of the denominators 9 and 6 is 18 so:

$= \frac{4 \cdot 2}{9 \cdot 2} + \frac{1 \cdot 3}{6 \cdot 3}$

$= \frac{8}{18} + \frac{3}{18}$

$= \frac{11}{18}$