Find the sum of the first 23 terms of an ap. 7,10.5,14
Answers
Answered by
0
solution: let a be the first term and d be the common difference of the given AP then we have
a=7 and d=(10-7)=3
now find the sum of 23 term of the given A.P.
Sn=n/2{2a+(n-1)d}
S23=23/2{2×7+(23-1)3}
S23=23/2{14+22×3}
S23=23/2{14+66}
S23=23/2×80
S23=23×40
S23=920
a=7 and d=(10-7)=3
now find the sum of 23 term of the given A.P.
Sn=n/2{2a+(n-1)d}
S23=23/2{2×7+(23-1)3}
S23=23/2{14+22×3}
S23=23/2{14+66}
S23=23/2×80
S23=23×40
S23=920
Similar questions