Hi I need help with these questions on binomial theorem!

1.) From the binomial expansion of , deduce that

Using T( r+1) I know the coefficient of is . I had let n in be 2n+1 and x be 1.

That way, I got Is this wrong because from here, I do not know how to get

2.) By considering the binomial expansion of , find

I got as an answer for this one, I had just expanded out the summation and then let x=1. It's wrong..

Thank you so much!