## Basic College Mathematics (9th Edition)

$\frac{4}{5}$
$\frac{1}{5}$ + $\frac{3}{5}$ = $\frac{1 + 3}{5}$ = $\frac{4}{5}$ Add the numerators $4$ is the sum of the numerators $5$ is the same denominator $\frac{4}{5}$ is already in lowest terms.