(x+y)²=x²+2xy+y²(平方)
1-x²+2xy-y²
|x+2y+3|+(2x+y)²=0求x²-xy+y²
已知x/y=3,求x²+2xy-3y²/x²-2xy+y²
x/y=2,求分式x²-xy+3y²/x²+xy+6y²
已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值
计算:(1).(-2xy²)*(3x²y)²
已知x²y²+x²+y²=10xy-16 求x,y
x²-4y²/x²+2xy+y²÷x+2y/2x²+2xy
xy²/(x²y-y) × x²/(x²+x)=
xy²/(x²y) - y×x²/(x²+x)=
已知X²-5XY+6Y²=0,求(X²+3XY)\2Y²的值
已知2x²-3y²=xy,(xy≠0),求值(4xy-x²)/(xy+2y²)的