Our first expression is
. Upon distributing the exponent 4 on all the terms, we get:

Therefore, your answer is correct for this part. :)
Second expression is
. Upon distributing the exponent -2 on all the terms, we get:

Your second answer is correct too.
Our third expression is
. Upon distributing the exponent 2 on all the terms, we get:

This one is not correct. Your answer would have been correct, if the exponent were -2 instead of 2 in this part.
Our forth and last expression is
. Upon distributing the exponent -5 on all the terms inside the parenthesis, we get:

Therefore, your answer for this part is also correct.
Looking at your work, I don't think you made a mistake in number 3 also, probably mis-typed the question while writing here :)