问题 填空题
已知a=
5
-
3
5
+
3
,b=
5
+
3
5
-
3
,则二次根式
a3+b3-367
的值是______.
答案

a=

5
-
3
5
+
3
=
8-2
15
2
=4-
15
,b=
5
+
3
5
-
3
=4+
15

∴a3+b3-367=(a+b)(a2-ab+b2)-367,

=(4-

15
+4+
15
)[(4-
15
2-(4-
15
)(4+
15
)+(4+
15
2]-367,

=8×[16+15-8

15
-(16-15)+16+15+8
15
]-367,

=8×(62-1)-367,

=488-367,

=121,

a3+b3-367
=11.

故答案为:11.

选择题
单项选择题