Question

In a geometric sequence, a2 = 2, a3 = 20, & a4 = 200.

Which equation can be used to find the nth term of the sequence, an?

an = 10 * 2n-1
an = 2n-1
an = 1/5 * 10n-1
an = 2 * 18n-1

Answer 1

C.) an =1/5 * 10n-1

Explanation:

D.) is out of the question just at first look.
A.) is irregular to the sequence, giving you the wrong outputs.
B.) is also irregular to the sequence.

Leaveing your answer...

Answer 2

the first one

the first one Explanation:

the first one Step-by-step explanation:from the formula Un =ar^n-1

where a is 2

where a is 2 r = 20/2=10

where a is 2 r = 20/2=10 so Un= 10×2^n-1

that's all.....have fun