If by quadruple you mean multiply by 4, then the quadruple of a cube would be 4x^3 and teh quadruple of a square is 4x^2.
However, I believe you are asking what happens to a square or a cube when you quadruple a side length. For the square you would get (4x)^2=16x^2 (the area increases by a factor of 16). For the cube you get (4x)^3=64x^3 (the volume increases by a factor of 64).
The area increases by the square of the increase in the side length, while the volume increases by the cube of the increase of the side length.
To quadruple something means to multiply it by 4, therefore, if we want to quadruple a cube, we'll have to multiply it by 4.
Let the cube of a value be `x^3` .
We'll quadruple the cube and we'll get: 4`x^3`
The same we'll do if we want to quadruple the square. Let the square be `x^2` , therefore the quadruple of square is: 4`x^2` .
Therefore, the quadruple of the cube is 4`x^3` and the quadruple of the square is 4`x^2` .