i just need verification, tell me if i am correct or not. if im incorrect please correct me.

1.By using the binomial expansion, show that:

i expanded the first two terms of (q+p)^n and -(q-p)^ n, then i added them together to get the exact statement above. is that fine or do i need a vigorous show to n terms?

2. what is the last term of the expansion if n is odd

if n is odd then the last two terms of (q+p)^n and -(q-p)^n are added together giving

3. what is the last term of the expansion if n is even

if n is even then the last two terms of and cancel each other leaving the second last term [tex] 2 (nC(k-1)) q. p^(k-1)