Question

若a^2/3+b^-1/3=4,x=a+3a^1/3*b^-2/3,y=b^-1+3a^2/3*b^-1/3 .则（x+

Answer 1

8

x+y=(a^1/3+b^1/3)^3

x-y=(a^1/3-b^1/3)^3

(x+y)^2/3+(x-y)^2/3=(a^1/3+b^1/3)^2+(a^1/3-b^1/3)^2=2(a^2/3+b^2/3)=8

我也在找这道题 额