ShirokovP

Verified answer

= a^3 + 6a^2*x + 12a*x^2 + 8x^3

morozovleonard (а+2х)^3=a^3+3a^2*2x+3a*(2x)^2+(2x)^3=a^3+6a^2x+3a*4x^2+8x^3=a^3+6a^2x+12ax^2+8x^3