Answer
To add or subtract two fractions with different denominators, find the lowest common denominator, and then subtract the two numerators.
Work Step by Step
For example:
$\frac{2}{3} - \frac{1}{5}$
The LCD of 3 and 5 is 15
Then subtract the numerators
$\frac{10}{15} - \frac{3}{15} = \frac{7}{15}$
