Find the sum : a-b/a+b + 3a-2b/a+b + 5a-3b/a+b + .....upto 11 terms.
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Answered by
47
c.d=a-b/a+b-(3a-2b/a+b)
=-2a+b/a+b
a3=a + 2d
5a-3b/a+b -(- 4a+2b/a+b)=a
9a-5b/a+b=a
s11=11/2(17a-10b/a+b + -20a+11b/a+b
s11=-33a+11b/2a+ 2b
=-2a+b/a+b
a3=a + 2d
5a-3b/a+b -(- 4a+2b/a+b)=a
9a-5b/a+b=a
s11=11/2(17a-10b/a+b + -20a+11b/a+b
s11=-33a+11b/2a+ 2b
yolo65:
guys pls dont follow this answer
pls follow the one bellow
a-b/a+b + 3a-2b/a+b + 5a-3b/a+b + ....
First term,a=a−ba+bCommon difference d=3a−2ba+b−a−ba+b=3a−2b−a+ba+b=2a−ba+bSn=n2(2a+(n−1)d)S11=112(2(a−ba+b)+10(2a−ba+b))=11(a−ba+b+5(2a−ba+b))=11(a−b+10a−5ba+b)=11(11a−6ba+b)=121a−66ba+b
First term,a=a−ba+bCommon difference d=3a−2ba+b−a−ba+b=3a−2b−a+ba+b=2a−ba+bSn=n2(2a+(n−1)d)S11=112(2(a−ba+b)+10(2a−ba+b))=11(a−ba+b+5(2a−ba+b))=11(a−b+10a−5ba+b)=11(11a−6ba+b)=121a−66ba+b
Answered by
4
Answer:
so answer is s¹¹ = 11/a+b(11a+6b)
Explanation:
we have to use sn=n/2{2a+(n-1)d}
formula
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