x=(根号3-根号2)/(根号3+根号2)=(根号3-根号2)^2/((根号3)^2-(根号2)^2) =5-2倍根号6 y=(根号3+根号2)/(根号3-根号2)=(根号3+根号2)^2/((根号3)^2-(根号2)^2)=5+2倍根号6 3x^2-5xy+3y^2=3(x^2-2xy+y^2)+xy =3(x-y)^2+(5-2倍根号6)(5+2倍根号6) =3(-4倍根号6)^2+5^2-(2倍根号6)^2 =288+1 =289