Question

What is the sum of the arithmetic sequence 22, 13, 4 … if there are 28 terms

1) 3,710
2) -3,094
3) -2,786
4) 4,018

Answer 1

3

Answer 2

y28=y1+(n-1)*d
d=y2-y1=13-22=-9
y28=22+27*(-9)=22-243=-221

Sn=(y1+y28)*14=-2786
next time use the formulas :)

Answer 3

i normally do the problem and then ask the question to make sure i have it right because im taking quizes and i want the best grade possible, but thanks.