∴a2-3a-1=a2-3a+abc=a(bc+a-3)=a(bc-b-c+1)=a(b-1)(c-1),
∴
a |
a2−3a−1 |
1 |
(b−1)(c−1) |
同理可得:
b |
b2−3b−1 |
1 |
(a−1)(c−1) |
c |
c2−3c−1 |
1 |
(a−1)(b−1) |
又
a |
a2−3a−1 |
b |
b2−3b−1 |
c |
c2−3c−1 |
4 |
9 |
∴
1 |
(b−1)(c−1) |
1 |
(a−1)(c−1) |
1 |
(a−1)(b−1) |
4 |
9 |
∴
(a−1)+(b−1)+(c−1) |
(a−1)(b−1)(c−1) |
4 |
9 |
4 |
9 |
整理得:
4 |
9 |
将abc=-1,a+b+c=4代入得:ab+bc+ac=-
1 |
4 |
则a2+b2+c2=(a+b+c)2-2(ab+bc+ac)=
33 |
2 |
故答案为:
33 |
2 |