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甲、乙两车分别从A、B两地出发,在A、B之间不断往返行驶,已知甲车的速度是每小时15千米,乙车的速度是每小时35千米,并且甲乙两车第三次相遇(这里特指面对面相遇)的地点与第四次相遇的地点恰好相距100千米,那么AB两地之间的距离是多少千米?老师常用的方法就是看相遇次数与全程关系,这确实很简单。我的方法有点麻烦,但对培养学生的思维大有好处。第一步:两车速度分别是15和35,这样可以求出两人速度比:15:35,也就是3:7。第二步:把全程平均分成10份,也就是把线段平均分成
A, B two vehicles respectively, starting from A, B, constantly moving between A, B, known speed of a car is 15 kilometers per hour, B car speed is 35 kilometers per hour, and A The second encounter between the two vehicles (specifically here to meet face to face) and the location of the fourth encounter just 100 km away, then the distance between AB two is how many kilometers? The teacher commonly used method is to see the number of encounters and Full relationship, this is really simple. My method is a little cumbersome, but it is good for developing students’ thinking. The first step: two car speed is 15 and 35, so you can find the two speed ratio: 15:35, which is 3: 7. The second step: the entire process is divided into an average of 10, that is, the average segment into