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