posted by hitarthi .
I tried till :
got stuck here as there is no commom cuming 5 and 2x n last sction.
I see a lot of perfect cubes there
8x^3 - 27y^3 = (2x-3y)(4x^2+6xy+9y^2)
Hmmm. No joy there.
wolframalpha.com factors it, but I can see no motivation for trying (2x-3y+5) as a factor.