If a, b, c are in GP, prove that
a2b2c2 [ ( 1 / a3 ) + ( 1 / b3 ) + ( 1 / c3 ) ] = a3 + b3 + c3
Here is the link given below for the answer similar to your query :
https://www.meritnation.com/ask-answer/question/propertion-prove-a3-b3-c3-a2b2c2-1-a3-1-b3-1-c3/math/1727538
https://www.meritnation.com/ask-answer/question/propertion-prove-a3-b3-c3-a2b2c2-1-a3-1-b3-1-c3/math/1727538