Find the 21st term of the arithmetic sequence: 18,23,28,33,...

asked Apr 28, 2016 102k views

5 votes

8.0k points

Please log in or register to add a comment.

6 votes

$18,23,28,33,... \\ a_1=18 \\ d=5 \\ \\ a_n=a_1+d(n-1) \\ a_(21)=a_1+20d \\ a_(21)=18+20 * 5 \\ a_(21)=18+100 \\ \boxed{a_(21)=118}$

7.7k points

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.5m questions

12.2m answers