Question

1+3+5+7+_______up to n terms is equal to​

Answer 1

Answer:

10

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Answer 2

A. P :- 1 + 3 + 5 + 7 + ............. + n

Sn = n/2 (1 + n)

= n/2 + n^2/2

= n + n^2/2.........(1)

Sn = n/2( 2(1)+ (n-1)2)

= n/2(2 + 2n - 2)

= n/2(2n)

= n^2............(2)

From eq (1) and (2)

➡ n+n^2/2 = n^2

➡ n + n^2 = 2n^2

➡ n = 2n^2 - n^2

➡ n = n^2 Ans