Multiply by fractions equal to one to make the denominators the same.

$-\frac{2}{3}\cdot\frac{5}{5}+\frac{4}{5}\cdot\frac{3}{3}=-\frac{10}{15}+\frac{12}{15}$

Change $2$ into a fraction greater than one.

Simplify before multiplying.

Multiply by the reciprocal.

$-\frac{1}{3}$