Can anyone explain this to me and how you got the answer please?

First, you're going to want to calculate the powers.
-3^2 = 9
2^3 = 8
Now your problem is:
9 + 8 x 6
Order of operations says you have to do the multiplication first.
8 x 6 = 48
Now your problem is:
9 + 48
9 + 48 = 57
Hope I could help!