简算:1/6+1/12+1/20+1/30+.1/72+1/90
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/29 14:30:21
简算:1/6+1/12+1/20+1/30+.1/72+1/90
![简算:1/6+1/12+1/20+1/30+.1/72+1/90](/uploads/image/z/17416221-69-1.jpg?t=%E7%AE%80%E7%AE%97%EF%BC%9A1%2F6%2B1%2F12%2B1%2F20%2B1%2F30%2B.1%2F72%2B1%2F90)
1/6+1/12+1/20+1/30+.1/72+1/90
=1/2*3+1/3*4+1/4*5...+1/9*10
=1/2-1/3+1/3-1/4+1/4...-1/10
=1/2-1/10
=2/5 应用公式1/n(n+1)=1/n-1/(n+1) 不理解可以问
=1/2*3+1/3*4+1/4*5...+1/9*10
=1/2-1/3+1/3-1/4+1/4...-1/10
=1/2-1/10
=2/5 应用公式1/n(n+1)=1/n-1/(n+1) 不理解可以问
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90简算
简算:1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
1/2+1/6+1/12+1/20+.+1/72+1/90简算
1/2+1/6+1/12+1/20+…+1/72+1/90简算
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+.1/9900
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/10
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110
谁能巧算1-1/2-1/6-1/12-1/20-1/30-1/42-1/56-1/72-1/90
1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110 急!
2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1等于多少
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