http://prntscr.com/ae0ykl @imqwerty

Question

imqwerty · Answer

tried this one? :)

hayhayz · Answer

Nope haven't attempted it but looking at it im gonna say it is either B or C?

hayhayz · Answer

I am getting a little mixed up on the equations from this lesson and the last lesson

hayhayz · Answer

Im leaning more on Option Cc though

imqwerty · Answer

the terms of a geometric sequence are of this from-

$\large \color{orangered}{a_n=a_1r^{n-1}}$

here $a_n$ is representing the $n^{th}$ term

you have this info-> $f(n)=500$
                     and ->   $g(n)= \large \left(\frac{9}{10}\right)^{n-1}$ 

relate $f(n)$ and $g(n)$ with $\color{orangered}{a_1}$ and $\color{orangered}{r^{n-1}}$  and replace $a_1$ and $r^{n-1}$ in that $a_n$ expression with the corresponding relative terms

the thing that you will get will be a GP

hayhayz · Answer

Ok I got it thank you :)

imqwerty · Answer

:) yw