已知3x^2-xy-4y^2=0(x≠y)求x/y的值

已知x^2+3xy-4y^2=0(y≠0),求x-y/x+y的值.已知x^2+3xy-4y^2=0(y≠0),求x-y/x+y的值. 已知x-y=4xy且xy≠0,求代数式-x-2xy+y分之2x+3xy-2y的值 已知x,y>0 2x+y+3=xy 求5x+4y最小值 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＞0,y＞0,x≠y,且x+y=x^2+y^2+xy,求证：1小于x+y小于4/3 已知3x²+xy-2y²=0(x≠0,y≠0),求x/y-y/x-x²+y²/xy的值 已知2x+3y=0,求代数式1.5x+4y/3x-2y 2.x²+xy-y²/x²-xy+y² 已知x^2-3xy+2y^2=0(xy≠0),则x/y+y/x= 已知xy≠0,且2x+3xy-2y=0,求(x+y)/(x-y)的值. 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-2|=0,求3x²y+{-2x²y-[-2xy+(x²y-4x²）]-xy} 已知3x^2-xy-4y^2=0(x≠y)求x/y的值 已知/X-Y-1/+(XY+3)的平方=0,求(-2XY+2X+3Y)-(3XY+2Y-2X)-(X+4Y+XY)的值!已知/X-Y-1/+(XY+3)的平方=0,求(-2XY+2X+3Y)-(3XY+2Y-2X)-(X+4Y+XY)的值急! 已知3＋XY－2y=0(x≠0,Y≠0)求x/y－y/x－x+y/xy 已知X-XY-2Y=0求2X+3XY-Y/X-2XY+5Y 已知x-y=4xy,求2x+3xy-2y/x-2xy-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