x²+3x+2=0
则：(x+2)(x+1)=0
x1=-2；x2=-1
(1) α=-2；β=-1
α²+2α-β=4-4+1=1
(2)α=-1；β=-2
α²+2α-β=1-2+2=1
所以,α²+2α-β=1