The problem is asking us to find the power "n" that will be needed to make the expression (-2) to the power "n" equal to 1 (one)
we recall that there is a very special exponent that when used on ANY real number different from zero gives as answer "1". That exponent is "0" (zero.
(-2)^0 = 1
So the exponent we are looking for is n = 0 (zero)