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1) find the value of a so that the term independent of x in the expansion of (rootx + a/x^{2})^{10} is 405.

2) if the coefficients of the 2nd term, 3rd term and 4th term in the expansion of (1+x)^{2n} are in ap then show that 2n^{2 }- 9n +7=0.

https://www.meritnation.com/ask-answer/question/find-value-of-a-so-that-the-term-independent-of-x-in-rootx/math/6906980

https://www.meritnation.com/ask-answer/question/the-coefficients-of-2nd-third-and-fourth-terms-in-the-expan/binomial-theorem/6840710

Regards

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