Find the cube root of 27a3+54ab2+36a2b+8a3

Answer 1

I think you mean
27a^3+54ab^2+36a^2b+8b^3
Note that 27a^3 and 8b^3 are perfect cubes
So the first thing that comes to mind is
(3a+2b)^3
I think you will find that that is what you want.