Let S = the sum of the first n terms of the given sequence.
The nth term will have coefficient (2n-1) and (n-1)st power of x.
So we have:
Multiply the sequence through by -x and add term by term to
the given sequence:
Can you finish from here?:
The n-1 terms between the first and last ones form a geometric
series. Use a formula for them, then you can solve for S.
If you have trouble, tell me in the thank-you note form below
and I'll get back to you by email. No charge as I do this
for fun.
Edwin
