(1/2+1/3+...+1/2014)(1+1/2+1/3...+1/2013)-(1+1/2+1/3+...+1/2014)(1/2+1/3+...+1/2013)七年级新观察“专题 有理数四则混合运算”T9
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/25 06:46:10
![(1/2+1/3+...+1/2014)(1+1/2+1/3...+1/2013)-(1+1/2+1/3+...+1/2014)(1/2+1/3+...+1/2013)七年级新观察“专题 有理数四则混合运算”T9](/uploads/image/z/1247468-68-8.jpg?t=%281%2F2%2B1%2F3%2B...%2B1%2F2014%29%281%2B1%2F2%2B1%2F3...%2B1%2F2013%29-%281%2B1%2F2%2B1%2F3%2B...%2B1%2F2014%29%281%2F2%2B1%2F3%2B...%2B1%2F2013%29%E4%B8%83%E5%B9%B4%E7%BA%A7%E6%96%B0%E8%A7%82%E5%AF%9F%E2%80%9C%E4%B8%93%E9%A2%98+%E6%9C%89%E7%90%86%E6%95%B0%E5%9B%9B%E5%88%99%E6%B7%B7%E5%90%88%E8%BF%90%E7%AE%97%E2%80%9DT9)
(1/2+1/3+...+1/2014)(1+1/2+1/3...+1/2013)-(1+1/2+1/3+...+1/2014)(1/2+1/3+...+1/2013)七年级新观察“专题 有理数四则混合运算”T9
(1/2+1/3+...+1/2014)(1+1/2+1/3...+1/2013)-(1+1/2+1/3+...+1/2014)(1/2+1/3+...+1/2013)
七年级新观察“专题 有理数四则混合运算”T9
(1/2+1/3+...+1/2014)(1+1/2+1/3...+1/2013)-(1+1/2+1/3+...+1/2014)(1/2+1/3+...+1/2013)七年级新观察“专题 有理数四则混合运算”T9
答:
设a=1/2+1/3+...+1/2014,b=1/2+1/3...+1/2013
(1/2+1/3+...+1/2014)(1+1/2+1/3...+1/2013)-(1+1/2+1/3+...+1/2014)(1/2+1/3+...+1/2013)
=a(1+b)-(1+a)b
=a+ab-b-ab
=a-b
=1/2014