Question directions simply state to simplify: (hehe, simply simplify)

(20+14sqrt(2))^(1/3) + (20-14sqrt(2))^(1/3)

WolframAlpha solution says to express 20 + 14√(2) as a cube to equal 8 + 12√(2) + 6((√2))^2+(√(2))^3. Can someone explain how these numbers were crunched up? Is it to do with (a^3+b^3)=(a+b)(a^2-ab+b^2)?