已知x(x-1)-(x^2-y)=-3求（二分之y-x+2xy)-xy 快,

已知x(x-1)-(x^2-y)=-3求（二分之y-x+2xy)-xy 快,
已知x(x-1)-(x^2-y)=-3求（二分之y-x+2xy)-xy 快,

已知x(x-1)-(x^2-y)=-3求（二分之y-x+2xy)-xy 快,
x(x-1)-(x^2-y)=-3
x²-x-x²+y=-3
y-x=-3
（y-x+2xy)/2 -xy
=(y-x)/2 +xy-xy
=（y-x）/ 2
=-3/2

x(x-1)-(x^2-y)=-3
x^2--x-x^2-+xy=-3
xy-x=-3
（二分之y-x+2xy)-xy
=y/2-x+2xy-xy
=y/2-x+xy
=y/2-3

-3.
若对于满足原式的x，y，后面的式子都成立的话，不妨设x=3，y=0；满足原式，带入后面的式子，解得值为-3.