(x-y)分之(x²+y²)+(y-x)分之(2x-y),其中x=3+√2,y=3-√2=(x²+y²)/(x-y)-(2x-y)/(x-y)=(x²+y²-2x+y)/(x-y)=[(3+√2)²+(3-√2)²-2*(3+√2)+3-√2)]/(3+√2-3+√2)=(9+6√2+2+...