已知x(x-1)-(x2-y)=-3求x2+y2/2-xy
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
已知x-y+1,X2+Y2=25 求(x+y)2和x2-xy+y2的值
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x(x-1)-(x2-y)=-3,求x2+y2-2xy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+y)2=25,xy=3,求x2+y2求x2+y2的值答案是?
已知实数x、y满足2x2-7xy+3y2=0,求x:y
已知:x=3,y=-5,x2-2xy+y2/x2-y2的值是
已知x+y=4,xy=2,求x2+y2+3xy的值.