The volume of the new sphere will be the sum of the volume of the two original spheres.
Volume of sphere with radius x:
V = [4 / 3] π (x^3)
Volume of the spher with radius [4/3] π (x +2)^3
Volume of the new sphere =
[4/3]πR^3 = [4/3]πx^3 + [/3]π(x+2)^3
R^3 = x^3 + (x+2)^3 = x^3 + x^3 + 3(x^2)(2) + 3x(2^2) + 2^3
R^3 = 2x^3 + 6x^2 + 12x + 8
Answer: R^3 = 2x^3 + 6x^2 + 12x + 8