geometric sequence quick question AS

hmm not sure if I've posted this thought I did but then I checked the recent posts in the maths forum but can't see mine.

please see attatchred having trouble figuing out how to use thee equations I've formed to show what they want me to show

Your first equation divided by your second equation = the "show that" equation.

Simple

oh right yeah I understand that


your method is neat but I don't see what you've done. I see that you've put the first equation equal to something else but please could you explain where the 'something else bit' has come from

He's literally done what I said.

Equation 1 = a(1-r^3)/(1-r)
Equation 2 = a/(1-r)
Equation 3 = (1-r^3)

Equation 1 / Equation 2 = Equation 3

So Equation 1 = Equation 2 x Equation 3 <- this is what he wrote

He's literally done what I said.

Equation 1 = a(1-r^3)/(1-r)
Equation 2 = a/(1-r)
Equation 3 = (1-r^3)

Equation 1 / Equation 2 = Equation 3

So Equation 1 = Equation 2 x Equation 3 <- this is what he wrote