How do you find the indicated term for the geometric sequence $a_{1} = 7$ $a_1=7$ , r=2, n=4?

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Answer 1 · 2017-08-13T16:42:24

Use the formula:

$a_{n} = a_{1} r^{n - 1}$ $a_n=a_1r^(n-1)$

Substitute 7 for $a_{1}$ $a_1$ , 2 for r, and 4 for n:

$a_{4} = 7 {(2)}^{4 - 1}$ $a_4=7(2)^(4-1)$

$a_{4} = 56$ $a_4= 56$

How do you find the indicated term for the geometric sequence a_1=7a1=7a_1=7, r=2, n=4?