These are so easy, you won't believe it !
A negative exponent only means
"Put all of this in the denominator, and make the exponent positive."
So (any number)^negative power =
1 / (the same number)^(the same power but not negative) .
The first few problems on that sheet:
1). 5^-3 = 1 / 5^3
2). 6^-10 = 1 / 6^10
3). (-2)^-5 = 1 / (-2)^5
Got it ? You can do the rest of them now in about 2 minutes.