问题
解答题
|
答案
+1 2
+5 6
+11 12
+19 20
+…+29 30
+9701 9702 9899 9900
=(1-
)+(1-1 2
)+(1-1 6
)+…+(1-1 12
)1 9900
=1×99-(
+1 2
+1 6
+…+1 12
),1 9900
=99-(
+1 1×2
+1 2×3
…+1 3×4
),1 99×100
=99-(1-
+1 2
-1 2
+1 3
-1 3
+…+1 4
-1 99
),1 100
=99-(1-
),1 100
=99-
,99 100
=98
.1 100