3/2-1/6+19/12-11/20+41/30-29/42+71/56 怎样用裂项解决,要过程.哥哥姐姐们,帮帮我吧!

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/08 04:16:48
3/2-1/6+19/12-11/20+41/30-29/42+71/56 怎样用裂项解决,要过程.哥哥姐姐们,帮帮我吧!

3/2-1/6+19/12-11/20+41/30-29/42+71/56 怎样用裂项解决,要过程.哥哥姐姐们,帮帮我吧!
3/2-1/6+19/12-11/20+41/30-29/42+71/56 怎样用裂项解决,要过程.
哥哥姐姐们,帮帮我吧!

3/2-1/6+19/12-11/20+41/30-29/42+71/56 怎样用裂项解决,要过程.哥哥姐姐们,帮帮我吧!
3/2-1/6+19/12-11/20+41/30-29/42+71/56
=1+1/2+1-1/2-1/3+1+1/3+1/4+1-1/4-1/5+1+1/5+1/6+1-1/6-1/7+1+1/7+1/8
=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+1/8
=7+1/8
=57/8

3/2-1/6+19/12-11/20+41/30-29/42+71/56
=(1+1/2)-(3-2)/6+1+(3+4)/12-2/20-(4+5)/20+1+(5+6)/30-1+(6+7)/42+1+(7+8)/56
=1+1/2-1/2+1/3+1+1/3+1/4-1/10-1/4-1/5+1+1/5+1/6-1+1/6+1/7+1+1/7+1/8
=3+2/3...

全部展开

3/2-1/6+19/12-11/20+41/30-29/42+71/56
=(1+1/2)-(3-2)/6+1+(3+4)/12-2/20-(4+5)/20+1+(5+6)/30-1+(6+7)/42+1+(7+8)/56
=1+1/2-1/2+1/3+1+1/3+1/4-1/10-1/4-1/5+1+1/5+1/6-1+1/6+1/7+1+1/7+1/8
=3+2/3-1/10+1/3+2/7+1/8
=4-1/10+2/7+1/8
=4-28/280+80/280+35/280
=4又280分之87

收起