Find the indicated term of the sequence.
-If the second term of a geometric progression is 45 and the third term is 9 , find $a _ { 1 }$ and $r$.
A) $a _ { 1 } = 225 ; r = 5$
B) $a _ { 1 } = \frac { 9 } { 5 } ; r = \frac { 1 } { 5 }$
C) $\mathrm { a } _ { 1 } = 405 ; \mathrm { r } = \frac { 1 } { 9 }$
D) $\mathrm { a } _ { 1 } = 225 ; \mathrm { r } = \frac { 1 } { 5 }$

Question

Quizplus · Accepted Answer

The second term is $a_1 \cdot r = 45$ and the third term is $a_1 \cdot r^2 = 9$. Solving these equations gives $r = \frac{1}{5}$ and $a_1 = 225$.

Find the Indicated Term of the Sequence a1a _ { 1 }a1​

Find the Indicated Term of the Sequence $a _ { 1 }$