Recent content by nomad2817

a)1024=1x-2^n-1 1024=-2^n-1? b) 2/27= 54x3^n-1?

Homework Statement Hi, there are two questions that I'm quite stuck with. 1.Find the number of terms in each of these geometric sequences. a) 1,-2,4...1024 b) 54,18,6...2/27 Homework Equations ar^n-1 The Attempt at a Solution 1. a) r= -2 1x-2^n-1 ? b)...

ohhhhh, i see now. Thank you

because 5^(5-1) which equals to 5^4

ohhhh n-1= 5-1?

n-1= 5

so it can be 625=25^2

1250= 2x so x=1250/2 x=625 oh no, I'm getting confused again. sorry

Thank you very much. I've just started learning about it, so I'm trying to get the hang of it, but thank you for helping me.

so do i have to balance both sides and eliminate 1250?

n is the term, but i don't know how to find it

i don't get what the next step is

Homework Statement Hi, I was trying to work out this question, but i kinda got stuck. Can anyone help me please? Thanks 4. Find the number of terms in each of these geometric sequences. 2,10,50...1250 Homework Equations ar^n-1 The Attempt at a Solution 1250=2x5^n-1