已知5x^2-4xy+y^2-2x+1=0,(x-y)^2006=?
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>0 2x+y+3=xy 求5x+4y最小值
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+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+5|=0,求3x^2y+{-2X^2y-[-2xy+(x^2y-4x^2)]-xy}
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
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^2+y^2+x^2y^2-4xy+1=0 求(x-y)^2008-(xy)^2008
已知X²+Y²+X²Y²-4XY+1=0 求:(X-Y)^2008-(XY)^2
已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y=
已知X+Y=2XY,求4X-5XY+4Y 除以X+XY+Y 的值
已知5x^2-4xy+y^2-2x+1=0,(x-y)^2006=?