已知x+y=5 x^2+y^2=13 求x^2y+2x^2y^2+xy^2
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x,y>0 2x+y+3=xy 求5x+4y最小值
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+2(xy+y)的值
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
已知X+Y=-1,xy=-2,求代数式-5(x+y)+(x-y)+(xy+y)的值
已知xy/(x+y)=2求(3x-5y+3y)/(-x+3xy-y)
已知xy/x+y=2,求代数式3x-5y+3y/-x+3xy-y
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方