When you square or cube a negative number is it still negative or does it become positive? Example:
(-4)^{2}

When you square a negative number, the result is positive.
(-4)^2 = (-4)ª(-4) = 16

When you cube a negative number, the result is negative.
(-4)^3 = (-4)•(-4)•(-4) = -64

Negatives pair up and cancel out, so odd exponents always have one negative unpaired, making the result negative.