Rewrite the expression. Use and exponent, rather than repeated multiplication (-4) (-4)

-4²

Any number repeatedly multiplied by itself has an exponent. so (-4) (-4) has an exponent of 2 while (-4) (-4) (-4) would have an exponent of 3 and be written as - 4³.

Also extra tip: Negative numbers multiplied by a negative number will always be positive.