Register

What is the sum of the arithmetic sequence 153, 139, 125, …, if there are 22 terms?

What is the sum of the arithmetic sequence 153, 139, 125, …, if there are 22 terms?
asked 182k views
4 votes
What is the sum of the arithmetic sequence 153, 139, 125, …, if there are 22 terms?

asked
User Selalerer
by
9.3k points

1 Answer

1 vote


a_1=153\\a_2=139\\a_3=125\\\vdots\\\\d=a_2-a_1\to d=139-153=-14

The formula of the sum of the arithmetic sequence:


S_n=(2a_1+(n-1)d)/(2)\cdot n

We have:


a_1=153\\d=-14\\n=22

substitute


S_(22)=(2\cdot153+(22-1)\cdot(-14))/(2)\cdot22=(306+21\cdot(-14))\cdot11=132

answered
User Sigcont
by
8.1k points
← Prev Question Next Question →

Related questions

User Avgvstvs
asked Aug 14, 2019 133k views
What is the sum of the arithmetic sequence 153, 139, 125, ..., if there are 22 terms?
Avgvstvs asked Aug 14, 2019
by Avgvstvs
8.7k points
2 answers
5 votes
133k views
Ask a Question
Welcome to Qamnty — a place to ask, share, and grow together. Join our community and get real answers from real people.

Categories

Other Questions

What is .725 as a fraction
How do you estimate of 4 5/8 X 1/3
A bathtub is being filled with water. After 3 minutes 4/5 of the tub is full. Assuming the rate is constant, how much longer will it take to fill the tub?
Link Copied!