Question

Find the indicated term of each arithmetic sequence.

$a_1=20,d=4,n=81$

Short answer

The indicated term of the arithmetic sequence is340.

Step-by-step solution

Step 1. Given Information.

Given indicated term of arithmetic sequence is $a_1=20,d=4,n=81$

Step 2. Calculation.

The n^th term of an arithmetic sequence is given by $a_n=a_1+(n-1)d$.

Here the first term is $a_1=20$

The common difference is $d=4$

And the required term is $n=81$

Plugging the values in the formula:

$\begin{array}{l}{a}_n=a_1+(n-1)d\\ a_{81}=20+(81-1)\left(4\right)\\ a_{81}=20+\left(80\right)\left(4\right)\\ a_{81}=20+320\\ a_{81}=340\end{array}$

Step 3. Conclusion.

Hence, the indicated term of the arithmetic sequence is 340.