Question

Find the sum of the first 22 terms of the AP 8, 3,_2.........

Answer 1

Answer:

Step-by-step explanation:

A=8 d=-5 n=22

An =a+(n-1)×d

= 8+(22-1)×(-5)

=8+(21)×(-5)

=8+105

=113

Answer 2

Given,

Series: 8,3,-2,.....

Here, a=8, d=a2-a1=3-8=-5,n=22

We know that,

sum of 'n' terms of an AP =

n/2[2a+(n-1)d]

22/2[2(8)+(22-1)(-5)]

=11[16+21(-5)]

=11(16-105)

=11(-89)

=-979

Therefore, sum of 22 terms of the given AP = -979

Hope this helps you:)