=[根号5(3根号3-根号2)+2根号3(3根号3-根号2)+(3根号3-根号2)]/(根号5+2根号3+1)=3根号3-根号2
=-根号2+(3根号3*根号5+3根号3+3根3*2根3)/(根号5+2根号3+1)=3根3-根2
