4x+y-4=0;2x^2+3y^2-4x=0怎么求x和y
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)}
若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*
若2x-3y=0,求5x+4y/3x-2y
已知4x-2y=0,求x-y/3x+2y的值
|x-2y|+√3x-4y =0求x y值
已知x,y>0 2x+y+3=xy 求5x+4y最小值
已知x^2+4y^2-4x+4y+5=0,求(y^4-x^4)/(y-2x)(x+y)*2x-y
已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
已知x.x+y.y+8x+6y+25=0,求代数式(x.x-4y.y)/(x.x+4xy+4y.y)-x/(x+2y)的
已知x,y满足{3x-y=9 {x-3y=0 求x+2y+ 4y的平方/x-2y -4x的平方y/x的平方-4y的平方