Exponents are the repeated multiplication of a
number. It is represented by the formula of a^n where a is the number to be
repeated and n is the number of times the number is being multiplies by itself.
Also include the sign of the number, no matter how it is multiplied, it is
still important. In this problem, you have 4 as the repeated number. You can
see that it is multiplied by itself by two times. So you have (-4)^2.