Register

What is the sum of the first 20 terms of the series 3 + 14 + 25 + 25 + 36 +

What is the sum of the first 20 terms of the series 3 + 14 + 25 + 25 + 36 +
asked 66.0k views
2 votes
What is the sum of the first 20 terms of the series 3 + 14 + 25 + 25 + 36 +

asked
User Willian Vieira
by
7.2k points

2 Answers

4 votes
2150 is the correct answer
answered
User Sarah
by
8.7k points
1 vote

Answer:


S _(20) = 2150

Explanation:


a _(1) = 3 \\ a _(2) = 14 \\ d = a _(2) - a_(1) = 14 - 3 = 11 \\ n = 20


S _(n) = (n)/(2) (2a + (n - 1)d) \\ \\ S _(20) = (20)/(2) (2(3) + (20 - 1) * 11) \\ \\ S _(20) = 10 * (6 + 19 * 11) \\ S _(20) = 10 * (6 + 209) \\ S _(20) = 10 * 215 \\ S _(20) = 2150

answered
User Cedomir Rackov
by
8.0k points
← Prev Question Next Question →

No related questions found

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

How do you can you solve this problem 37 + y = 87; y =
What is .725 as a fraction
How do you estimate of 4 5/8 X 1/3
Link Copied!