## Algebra 1: Common Core (15th Edition)

-$\frac{7}{15}$
We need a common denominator (bottom of the fraction) to add the numerators (tops of the fractions). Thus, we multiply $\frac{1}{5}$ by $\frac{3}{3}$ to get $\frac{3}{15}$ and multiply -$\frac{2}{3}$ by $\frac{5}{5}$ to get -$\frac{10}{15}$. (This is legal because $\frac{3}{3}$ and $\frac{5}{5}$ are equal to one). We now have: $\frac{3}{15}$+(-$\frac{10}{15}$)=-$\frac{7}{15}$ (Recall, adding a negative is the same as subtraction.)