a的4/3次方-8a的1/3次方b/[4b的2/3次方+2a的1/3次方b的1/3次方+a的2/3次方][a的1/3次方-2b的1/3次方]=a^(1/3)(a-8b)/[4b^(2/3)+2a^(1/3)b^(1/3)+a^(2/3)][a^(1/3)-2b^(1/3)]=a^(1/3)(a-8b)/(a-8b)=a^(1/3)...