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9.6Solve following questions.The sum of the first n natural numbersis given by the relation S = n(n+1) Findn if the sum is 55. |
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Answer» n( n+1)/2 = 55; n^2+ n = 55(2); n^2 + n =110, n^2+ n -110; n^2+11n -10n -110=0; n( n+11)-10( n+11); ( n + 11)( n-10); n = -11/10 |
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