已知x^2+y^2-4x+y+4又1/4=0,求x^2+9y^2
已知4x=9y求(1)x+y/y (2)y-x/2x
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.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y
已知|x|=12又4分之3,|y|=8又2分之1,并且|x+y|≠x+y,求x+y的值
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
(3x-2y)(4x-5y)-11(x+y)(x-y)+5xy,已知X=3又1/2,y=2又1/3
已知x^2+4y^2-4x+4y+5=0,求(y^4-x^4)/(y-2x)(x+y)*2x-y
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
已知x²+y²+5=2x+4y,求代数式(2x²-(x+y)(x-y))x((x+y-1)