2d+f=-4 ⑴
d+3e+f=-10 ⑵
-d+e+f=-2 ⑶
⑵+⑶,得4e+2f=-12,
2e+f=-6=>f=-6-2e,代入⑴,得d=1+e
将f=-6-2e,d=1+e代入⑶
-(1+e)+e-6-2e=-2=>e=-5/2=-2.5,则
d=1+e=1-5/2=-3/2=-1.5
f=-6-2e=-6-2(-5/2)=-1
于是,d=-3/2=-1.5 e=-5/2=-2.5 f=-1