已知:x+y=10,xy=9,求x-y

已知x-xy=8,xy-y=-9,求x+y-2xy的值 已知2x+xy=10,3y+2xy=6.求4x+8xy+9y=? 已知x-y=9,xy=5.求(x+y)(x+y)的值? 已知x-y=9,xy=负20,求（x+y)(x+y) 已知X+y=10,XY=24,求(X-Y)(X-Y)的值 已知x^2-6xy+9y^2=0,求(x-y)/(x+y) 已知x,y满足xy-x-y=10,求整数x,y的值 已知x²y²+x²+y²=10xy-16 求x,y 已知:x+y=10,xy=9,求x-y 已知x^2+9y^2-2x-6y+2=0,求{-（xy/（x-y）^2}^4*(y^2-xy/x)^3*x^4/y^10/(x/xy-y^2)^5的值 已知x+y=12,xy=9,求(x+3xy+y)/(xy+xy)的值 已知(1/x)-(1/y)=5,求(6x+7xy-6y)/(8y-9xy-8y) 已知(x+y)(x+y)=25,(x-y)(x-y)=9求xy与xx+yy的值 已知x+y+yz=5,y+z+xy=8,x+z+xy=9,求x,y,z 已知X+Y=3,XY=-1,求2(X-Y)^4-9(X-Y)^2+12XY 已知x+y=3,xy=-10,求（1）x平方-xy+y平方；（2）|x-y| 已知x+y=-2,求代数式(6xy+10y)+[4x-2(3xy+2y-x)] 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?