1/3+1/15+1/35+1/63+1/99+1/143=_.
问题描述:
+1 3
+1 15
+1 35
+1 63
+1 99
=______. 1 143
答
+1 3
+1 15
+1 35
+1 63
+1 99
,1 143
=[(1-
)+(1 3
-1 3
)+(1 5
-1 5
)+(1 7
-1 7
)+(1 9
-1 9
)+(1 11
-1 11
)]×1 13
,1 2
=[1-
]×1 13
,1 2
=
×12 13
,1 2
=
;6 13
故答案为:
.6 13