- Thread starter
- #1

Sn = 33

tn = 48

r = -2

I know that I have to take the formulas tn = t1 x r^(n-1), and Sn = [t1 x (r^n) - 1] / (r - 1), and isolate t1 for the first formula and then input that into the second, but I don't know the actual process of doing that.

If anyone can explain it step by step and with reasons maybe, that would be really helpful, I'm not good at math and get confused easily. Any help is appreciated