SOLUTION: In the expansion of (2x+1)^n, the coefficient of the x^2 term is 40n , where n is a positive integer. Find the value of n.

Question 1181925: In the expansion of (2x+1)^n, the coefficient of the x^2 term is 40n , where n is a positive integer. Find the value of n.
Answer by ikleyn(52787) (Show Source): You can put this solution on YOUR website!
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In the expansion of (2x+1)^n, the coefficient of the x^2 term is 40n ,
where n is a positive integer. Find the value of n.
~~~~~~~~~~~~~~~~~~~~

The coefficient at x^2 is   = ,


so we have this equation


     = 40n,  or


     = 10

    n-1 = 20

    n = 21.        ANSWER

Solved.

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