Question

(a+b/3)(a*2-1/3ab+1/9b*2)如何化简

Answer 1

∵有立方和公式：x^3+y^3=(x+y)(x^2-xy+y^2)

令x=a,y=b/3,即可得

a^3+(b/3)^3=(a+b/3)(a^2-1/3ab+1/9b^2)

∴(a+b/3)(a^2-1/3ab+1/9b^2)=a^3+(b/3)^3=a^3+(b^3)/27

注：a^x表示a的x次幂,数学中大多都是这样表示的,