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

User Willian Vieira
by
5.1k points

2 Answers

4 votes
2150 is the correct answer
User Sarah
by
5.7k 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

User Cedomir Rackov
by
5.6k points
Ask a Question
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

6.0m questions

7.8m answers

Other Questions

Solve for y in terms of x. 2/3y - 4 = x y = x + 6 y = -x + 4 y = -x + 6 y = x + 4
Aliyah has $24 to spend on seven pencils. After buying them she had $10. How much did each pencil cost?
Ten gallons of paint were poured into two containers of different sizes. Use one variable to express the amount poured into each container
Use the normal model ​n(11371137​,9696​) for the weights of steers. ​a) what weight represents the 3737thth ​percentile? ​b) what weight represents the 9999thth ​percentile? ​c) what's the iqr of the weights
Evaluate a + b when a = –16.2 and b = –11.4 A. –27.6 B. –4.8 C. 4.8 D. 27.6
Link Copied!