find a6 for the geometric sequence with a1=5, r=2?

0 ⤊

answers:
32
4
80
180

2007-03-03 03:29:25 · 5 answers · asked by julie s 1 in Science & Mathematics ➔ Mathematics

y = a1(r)^(n-1)

y = 5(2)^(6-1)

y = 160

answer is not in the list

2007-03-03 03:35:03 · answer #1 · answered by 7 · 0⤊ 0⤋

a6 =a1.r^5=5(2^5)=5(32)=160

2007-03-03 11:39:50 · answer #2 · answered by llcold 2 · 0⤊ 0⤋

a[n] = a[1] x r^(n-1)

a[6] = 5 x 2^(6-1) = 5(2^5) = 5 x 32 = 160.

answers not in ur list, friend

2007-03-03 12:16:04 · answer #3 · answered by Anonymous · 0⤊ 0⤋

an = a1xr^n

Thus for r = 2 n= 5 you get r5 = 80

2007-03-03 11:36:57 · answer #4 · answered by physicist 4 · 0⤊ 0⤋

what is the sequence or question of a6?

2007-03-03 11:34:16 · answer #5 · answered by tomkat1528 5 · 0⤊ 0⤋