Negative exponents work like this:

So, in order to evaluate a negative exponent, you simply have to invert the base, and then raise to the positive equivalent of the exponent.
As an example, here are the first three exercises:



You can work out the rest applying this logic.
Answer:
x-15
Step-by-step explanation:
Th three numbers he could of had on his uniform are 60 30 or 90
The answer would be 64 inches or 5 feet 4 inches.
3 yards is equal to 108 inches and 1 foot is equal to 12 inches which equals 120 inches
120-56=64