45km/h
设速度为x
(60 - x ) x 5 = (70 - x ) x 3
2x=90
x=45
算数 60x5 - 70x3 =90
5 - 3 =2
90 ÷ 2=45
设乙车速度为x
(60-x)*5=(70-x)*3
解得x=45km/h
设乙车速度为X
则 5(60-X)=3(70-X)
解得 X=45
答案是45km/h
解:设乙车速度为x,由题意可得
(60 - x ) x 5 = (70 - x ) x 3
300-5x=210-3x
2x=90
x=45