若y=√1-2x+√2x_1+1/2,求√x2+y2-√x2+y2+2xy=?
已知x2+4y2+x2y2-6xy+1=0,求 x4-y4/2x-y 乘 2xy-y2/xy-y2 除以(x2+y2/x
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
若X2+Y2-2X-6Y+10=0 ,求(x2-y2)/xy的值
已知x-y+1,X2+Y2=25 求(x+y)2和x2-xy+y2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
若x2-2xy-y2-x+Y-1=0 求x-y的值
已知实数x.y满足(x2+y2)(x2+y2-1)=2,求x2+y2的值
当x=2,y=1 求{(x2+y2)/(x2-2xy+y2)+(2)/xy÷[(1/x)-(1/y)]}÷(x+y)的值
已知x2-2xy=3y2且x,y为非零实数 求:(1)2x+y/x-2y (2)2x2-3y2+5xy/x2+xy+y2
已知圆x2+y2-2x-2y+1=0求x2+y2的最大值