计算题:-1/2+1/6+1/12+1/20+1/30+1/42
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:2024/06/28 07:19:29
计算题:-1/2+1/6+1/12+1/20+1/30+1/42
![计算题:-1/2+1/6+1/12+1/20+1/30+1/42](/uploads/image/z/17174696-32-6.jpg?t=%E8%AE%A1%E7%AE%97%E9%A2%98%EF%BC%9A-1%2F2%2B1%2F6%2B1%2F12%2B1%2F20%2B1%2F30%2B1%2F42)
-1/2+1/6+1/12+1/20+1/30+1/42
=-1/2+1/2*3+1/3*4+1/4*5+1/5*6+1/6*7
=-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7
=-1/7
=-1/2+1/2*3+1/3*4+1/4*5+1/5*6+1/6*7
=-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7
=-1/7