The 3rd, 4th and 5th terms in the expansion of (x + a)n are respectively 84, 280 and 560, find the values of x, a and n.

Part (3) of the question is the solution to your answer:

https://www.meritnation.com/ask-answer/question/84-280-and-560-find-the-values-of-x-a-and-n/math/3441741

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