问题
填空题
设x=
|
答案
∵x=
=7+42+ 3 2- 3
,y=3
=7-42- 3 2+ 3
,3
∴x+y=14,xy=49-48=1,
∴x3+y3=(x+y)(x2-xy+y2)
=(x+y)[(x+y)2-3xy]
=14×(142-3×1)
=2702.
故答案为2702.
设x=
|
∵x=
=7+42+ 3 2- 3
,y=3
=7-42- 3 2+ 3
,3
∴x+y=14,xy=49-48=1,
∴x3+y3=(x+y)(x2-xy+y2)
=(x+y)[(x+y)2-3xy]
=14×(142-3×1)
=2702.
故答案为2702.