find the 11th term of the following geometric sequence. 5, 20, 80, 320, ...
find the 11th term of the following geometric sequence. 5, 20, 80, 320, ...
Answer
Answer:
$5\times4^{10}$
Explanation:
Step1: Identify the first - term and common ratio
The first - term $a_1 = 5$. The common ratio $r=\frac{20}{5}=4$.
Step2: Use the formula for the nth term of a geometric sequence
The formula for the nth term of a geometric sequence is $a_n=a_1\times r^{n - 1}$. Here, $n = 11$, $a_1 = 5$, and $r = 4$. So, $a_{11}=5\times4^{11 - 1}=5\times4^{10}$.