Hi, I'm having some problems with a few questions. I'm not cheating because we are given the answers and the work is not for marks. Please see Attached document Numbers
Section A: 5
Section B: 6, 8,9
Please help :/
5 A) I'm not sure if I'm seeing correctly, but I think the top part of the summation is a 6? If so, it's just 2^2+2^3+2^4+2^5+2^6=124
8 B) Use Binomial-theorem
9 B) Let the first term be x and the common ratio be y:
Second term= xy
Third term= xy^2
...
Fifth term=xy^4
We know x=18, so 18(y^4)=32/9
And you can use that to find y
And we know 8th term is x(y^7), and knowing x and y, we can get an answer.