则(1)得
(x-2y)(x-y)=0
x-2y=0 x-y=0
∴可组成两个方程组
x-2y=0 x-y=0
x+y=6 x+y=6
∴x=4 x=3
y=2 y=3
(x²-6)(x²+2)=0
(x+√6)(x-√6)(x²+2)=0
∴x=-√6 x=√6