Find a common denominator and simplify.

$\left(-\frac{4}{5}\right)\left(\frac{12}{12}\right)+\left(\frac{7}{12}\right)\left(\frac{5}{5}\right)$

$-\frac{13}{60}$

Remember that adding a negative number is essentially subtraction.

$\frac{11}{36}$

Multiply the numerators together and the denominators together.

Turning the first fraction into a fraction greater than one may prove to be more helpful.