Hello. I am having trouble with four problems from my homework.

I don't know why but the answers I get seem wrong and I am not quite sure what I am doing. (although happily i think I completed the rest with no problems yay! just these four are killing me!)

I also am in a situation where I can't spend too much time online so any help is appreciated!

I guess I can start with two questions.

I need to make a substitution and then evaluate the integral but i think i am doing the substitution part incorrectly.

and

thank you!