Find four numbers forming a geometric progression in which the third term is greater than the first terms by 9, and second term is greater than the 4th by 18.

Explanation

Let the four numbers in G.P. be a,ar,ar^2,ar^3


Thus, ar^2=a+9 and ar=ar^3+18


`=>ar^2−a=9` and `ar−ar^3=18
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Now~ `ar^2−a=9⇒a^2r−1=9....(1)
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