Any number to a negative power, can be solved by flipping it (reciporacle) and making the exponent positive.
Anything to the -1 power (like h) equals 1/h^1
so yourequation is (1/h^1)=.5
h^1 is just h, so the problem simplifies to 1/h = .5
the fraction form of .5 is 1/2 so 1/h=1/2
cross multiply, and you get h=2
so the answer is two