第1个回答 2013-11-02
设船速为x km/h 水速为y km/h
逆流航行时 实际船速=船速-水速 则逆流航行时实际船速=x-y
顺流航行时 实际船速=船速+水速 则顺流航行时实际船速=x+y
360/(x+y)+360/(x-y)=35 ①
360/(x-y)-360/(x+y)=5 ②
①+②
360/(x+y)+360/(x-y)+360/(x-y)-360/(x+y)=35+5
2*360/(x-y)=40
2*360/40= x-y
x-y=18
把x-y=18带入①中
360/(x+y)+360/18=35
360/(x+y)=35-20
360/(x+y)=15
x+y=360/15
x+y=24
x+y=24③
x-y=18④
③+④
x+y+x-y=24+18
2x=42
x=21
把 x=21 带入③中
21-y=24
y=3
答:船速为21km/h 水速为3km/h