已知:3X^2+XY-2Y^2=0,求(X+Y)/(X-Y)+4XY/(Y^2-X^2)÷(X^2+2XY-3Y^2)/
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
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=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知y-x-2xy=0,求3x+xy-3y/y-xy-x的值
已知y-x-2xy=0,求(3x+xy-3y)\(y-xy-x)的值
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>0 2x+y+3=xy 求5x+4y最小值
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知x-y=4xy,则2x+3xy-2yx-2xy-y
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)