Showing a binomial expansion

[Wiz]

Hi, I was working through my binomial expansion exercise when I came through question 16. I have no idea what to do with this. Like, how do I show that L.H.S = R.H.S? Should I even be trying to show it like that? I would really appreciate it if someone can point me in the right direction.

 

[HallsofIvy]

Which problem are you referring to, 16? If so then you do what is suggested, "consider \(\displaystyle (1+ x)^n(1+ x)^n= (1+ x)^{2n}\)" by writing the binomial formula expansion of both sides.

 

[Wiz]

Which problem are you referring to, 16? If so then you do what is suggested, "consider \(\displaystyle (1+ x)^n(1+ x)^n= (1+ x)^{2n}\)" by writing the binomial formula expansion of both sides.

I expanded both sides:

but I still don't see how I can answer the question. Can I just sort of turn (2n 1) into (n 1)^(2)?