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If `x=-""^(n)C_(1)+""^(n)C_(2)(2)-""^(n)C_(3)(2)^(2)+....` (where n is odd), then x=___________A. 1B. `-1`C. 0D. 12

Answer» Correct Answer - B
Given `x=-""^(n)C_(1)+""^(n)C_(2)(2)....`
`2x=-""^(n)C_(1)(2)+""^(n)C_(2)(2)^(2)-""^(n)C_(3)(2)^(3)+.....`
`1+2x=1-""^(n)C_(1)(2)+""^(n)C_(2)(2)^(2)-""^(n)C_(3)(2)^(3)+.....`
`1+2x=(1-2)^(n)`
`1+2x=(-1)^(n)`
`1+2x=-1` (given n is odd)
`2x=-2`
`x=-1`


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