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.
You have to subtract 3.2 from 3.5 to get x. 0.3+ 3.2=2.5 so x=0.3
I hate study island lol and are those supposed to be powers? Like 3 to the power of 8
Given width is 24 less than length.
W=L-24
Perimeter = 2(W+L)=2(L-24+L)=4L-48
But we're also given perimeter = 172'
Therefore 4L-48=172
solve for L
4L=172+48=220
L=55'
W=55-24 = 31'
Check: Perimeter = 2(W+L)=2(31+55)=2*86=172' good!
Answer: The dimensions of the garden are 31' * 55'
The answer is going to be D