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乙步行了x千米，丙步行了y千米，甲共走了28-x+28-x-y+28-y=84-2x-2y甲共用时(84-2x-2y)/44乙共用时x/5+(28-x)/44丙共用时y/5+(28-x)/44(84-2x-2y)/44=x/5+(28-x)/44,84-2x-2y=44x/5+28-x,56*5=49x+10y(84-2x-2y)/44=y/5+(28-y)/44,84-2x-2y=44y/5+28-y,56*5=49y+10x560=59x+59y,x+y=560/59,x=560/59-y,280=49y+5600/59-10y,y=(280-5600/59)/39y=(280*59-5600)/59*39=280(59-20)/39*59=280/59x=280/59乙步行了140/177小时 |
