已知：x+y=2,2y²-y-4=0,求y-x/y的值

已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y 已知：x+y=2,2y²-y-4=0,求y-x/y的值 已知x²+y²-4x+6y+13=0,求x²+2y/x²-3y²的值 已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y的值 已知x²+4x+y²-10y+29=0 求【x+2y】÷【x²-2y²】的值 已知：x²+4x+y²-+6y+13=0,求x-2y/x²+y²的值. 已知x²+y²+8x+6y+25=0,求x-4y/x+y的值 已知：x²+y²+4x+6y+13=0 求：x²+y²的值 已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值 已知x²+y²-6x+4y+13=0,求(2x-y)²-2(2x-y)(x+2y)+(x+ 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 已知4x²-3y²=7,3y²+2y²=19,求14x²-2y的值