牛粪禁止插花儿
幼苗
共回答了20个问题采纳率:90% 举报
A___小镇D________C____休息地E___B
如图:AC-BC=100,
AD=1/3AC,
DE=400,
BE=1/2CE,
BE=2/3AC,
AB=AC+BC
=AC+(AC-100)
=2AC-100
=2 x 3AD-100
=6AD-100
=6 x 1/2DC-100
=3DC-100
=3 x (400-CE)-100
=1200-3CE-100
=1100-3CE
=1100-3 x (2BE)=1100-6BE
又AB=AC+BC=2AC-100=2 x 3/2 x BE
=3BE
则1100-6BE=3BE
则9BE=1100,BE=1100/9
则AB=3BE=1100/3千米
1年前
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