仿照例題做吧：
例題：同一直線上有A B C D四點(diǎn),已知AB=5/9DB,AC=9/5CB,且CD=4cm,求線段AB的長(zhǎng).
①當(dāng)ABCD四個(gè)點(diǎn)按A-D-C-B排列時(shí)：滿足AD+DB=AB=AC+CB
AB=AD+DB=5/9DB+DB,所以DB=9/14AB,AD=5/14AB
AB=AC+CB=9/5CB+CB,所以CB=5/14AB,AC=9/14AB
所以CD=AC-AD=2/7AB=4,AB=3.5×CD=14
②當(dāng)ABCD四個(gè)點(diǎn)按C-B-A-D排列時(shí)：滿足BD-AD=AB=AC-CB
AB=BD-AD=BD-5/9BD,所以BD=9/4AB,AD=5/4AB
AB=AC-BC=9/5CB-CB,所以BC=5/4AB,AC=9/4AB
所以CD=CB+AB+AD=5/4AB+AB+5/4AB=7/2AB,AB=8/7
③當(dāng)ABCD四個(gè)點(diǎn)按C-B-D-A排列時(shí)：滿足AD+DB=AB=AC-BC
AB=AD+DB=5/9DB+DB,所以DB=9/14AB,AD=5/14AB
AB=AC-BC=9/5CB-CB,所以BC=5/4AB,AC=9/4AB
所以CD=BC+BD=5/4AB+9/14AB=53/28AB,AB=112/53
④當(dāng)ABCD四個(gè)點(diǎn)按D-A-C-B排列時(shí)：滿足BD-AD=AB=AC+BC
AB=BD-AD=BD-5/9BD,所以BD=9/4AB,AD=5/4AB
AB=AC+CB=9/5CB+CB,所以CB=5/14AB,AC=9/14AB
所以CD=AD+AC=5/4AB+9/14AB=53/28AB,AB=112/53
同類型題目,認(rèn)真計(jì)算一下吧!