x^2-y^2-y-4=0
(x-2y)(x+y)=0
联立起来解方程组
參考答案:由(x-2y)(x+y)=0得x=2y或x=-y
当x=2y时 2y*2y-y*y-y-4=0 (y+1)(3y-4)=0 y=-1或y=4/3
当x=-y时 -y*(-y)-y*y-y-4=0 y=-4
所以y=-1或y=4/3或y=-4
x^2-y^2-y-4=0
(x-2y)(x+y)=0
联立起来解方程组
參考答案:由(x-2y)(x+y)=0得x=2y或x=-y
当x=2y时 2y*2y-y*y-y-4=0 (y+1)(3y-4)=0 y=-1或y=4/3
当x=-y时 -y*(-y)-y*y-y-4=0 y=-4
所以y=-1或y=4/3或y=-4