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Find a, b and n in the expansion of (a + b)n if the first three terms of the expansion are 729, 7290 and 30375, respectively.

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It is known that (+ 1)th term, (T r +1), in the binomial expansion of (b) n is given by image.

The first three terms of the expansion are given as 729, 7290, and 30375 respectively.

So, we obtain

Dividing equation 2 by 1 we get

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