因为：
1/2＝1-1/2
1/6＝1/2-1/3
1/12＝1/3-1/4
……
1/90＝1/9-1/10
所以,
原式＝1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10
＝1-1/10＝9/10
不通分计算1/2+1/6+1/12+1/20+1/30+1+42+1/56+1/72+1/90
2个回答
相关问题
-
计算：1/2+1/6+1/12+1/20+/+1/30+1/42+1/56+1/72+1/90
-
计算1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
-
1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90简便计算
-
计算1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110=?
-
计算1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110=?
-
2\1-6\1-12\1-20\1-30\1-42\1-56\1-72\1-90\1
-
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90=
-
2/1＋6/1＋12/1＋20/1＋30/1＋42/1＋56/1＋72/1＋90/1
-
1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
-
1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90=?