若|3x-1|+(2y+1)2=0,求2x2+3y2/x-y的值
已知x2-4x-1=0,求代数式(2x-3)2-(x+y)(x-y)-y2的值
若x2-2xy-y2-x+Y-1=0 求x-y的值
x(x-1)-(x2-y)=-3,求x2-y2-2xy的值
x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
已知x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知2x+y=7,x2+y2=5,求(4x+2y)2-3x2-y2+2(1-y2)的值.
已知[(x2+y2)-(x-y)2+2y(x-y)]÷4y=1,求4x/4x2-4y2-1/2x+y的值,
(x+y)(x+y+1)=0 求x2+y2+2xy的值
若X2+Y2-2X-6Y+10=0 ,求(x2-y2)/xy的值
已知圆x2+y2-2x-2y+1=0求x2+y2的最大值
已知实数x.y满足(x2+y2)(x2+y2-1)=2,求x2+y2的值