x^2+y^2=10,x-y=4,求x,y x+y=-5,xy=4,求x-y x+y=9,xy
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
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*
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
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X+Y=2XY,求4X-5XY+4Y 除以X+XY+Y 的值
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
已知2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y (4xy-2y²)/4
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值
2x+y=0,求4x²+2xy(x+y)+y³
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}