Answer of this question

The Arithematic Progression is a sequance in which every term is obtained by adding or substacting a "FIXED NUMBER" to preceding term except first term. The first term is called "a" and the FIXED NUMBER is called "COMMON DIFFERENCE".
See the AP is 8,3,-2.......  not 3,3,-2... because it's not an AP.
a=8 d=-5.
Sn= (n/2)[2a+(n-1)d] where, n= No. Of terms. a=first term, d= Common difference and Sn is Sum of n terms
Substituting the values of n,a and d we get
S22=(22/2)[2(8)+(22-1)(-5)]
       =(11)[16-105]
       =(11)[-89]
       =-979
Hence Sum of 22 terms of AP 8,3,-2..... is -979

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Written on June 11, 2021, 10:37 a.m.