find (4-1/n )+(7-2/n)+(10-3/n)............upto n terms class 10
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Answered by
70
see photo given below
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a little error is here
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2nd last step
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1/2 (5n+3n^2-n-1)
1/2 (3n^2+4n-1)
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a little error is here
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2nd last step
..................................
1/2 (5n+3n^2-n-1)
1/2 (3n^2+4n-1)
Attachments:
nandunadz:
ok
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1/2 (5n+3n^2-n-1)
1/2 (3n^2+4n-1)
but
that is complex
1st term = 4-1/n
common difference = 3-1/n
substitute these values in SUM equation
its getting complex while u proceed
Answered by
32
Answer:Hope u will understand
Like plz
Step-by-step explanation:
==》4-1/n + 7-2/n + 10-3/n
==》(4+7+10....) - [(1/n) + (2/n) + (3/n).....]
==》n/2 [8+(n-1)3] - 1/n [n(n-1)/2]
==》n/2 (5+3n) = (n-1/2)
==》1/2 (5n+3n^2-3n-3)
==》1/2 (3n^2-2n+3).........Ans.
==》Plz like
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