# Math Help - Another geometric sequence ?

1. ## Another geometric sequence ?

A5= 24
r=2
Find A1.

hmmmm..I'm not sure how to do this one. I was absent the day we learned this in class. Thanks in advance.

2. $a_n = a_1 r^{n - 1}$

3. 24=A1(1)

....uuuhh....

?

I'm going off of memory here from my algebra class last year. I was absent the day this was taught in class, so I have no notes, and the textbook doesn't go over this.

4. OH NO.
It would be this:
24=A1(16), then solve for A1.
yeeeeeeeees?

5. Originally Posted by beetz
OH NO.
It would be this:
24=A1(16), then solve for A1.
yeeeeeeeees?
yes