It’s 54.8 I’m pretty sure
(I hope this helps!)
The subtraction sign in front of the second set of parenthesis changes the signs on the terms inside those parenthesis. So this could be rewritten as

. None of the exponents on the x are the same, so we will just express it in terms of descending powers of x.

. This is also the same as

if you don't like to start with a negative. Either one is correct.
It should me b I don’t know if it is but it should be
89 is prime 16 is composite 17 is prime 25 is composite
The awnser for question 5 is 4/6