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The two trains, car a and car B, are 200 meters long and 280 meters long. They run opposite each other on parallel tracks. It is known that after 40 seconds from the head of car a catching up with the tail of car B to the departure of the two cars, the speed ratio of car a and car B is 5:3. What is the speed of the two cars? I want a univariate equation!
Let a's speed be 5x meters per second and B's speed be 3x meters per second
(5x-3x)*40=200+280
2x*40=480
80x=480
x=6
5x=5*6=30
3x=3*6=18
A: the speed of a is 30 meters per second and that of B is 18 meters per second
The speed ratio of train a and train B is 5:4. Train B starts first and drives from station B to station A. when it comes to a place 72 kilometers away from station B, train a starts from station a to station B. the distance ratio between the place where the two trains meet and station a and station B is 3:4. What is the distance between station a and station B?
Three for car a and three for car B × 4 / 5 = 2.4 copies,
72km is equivalent to 4-2.4 = 1.6 parts,
Each is 72 ÷ 1.6 = 45km,
So the distance between stations a and B is 45 × (3 + 4) = 315 (km)
A: the distance between stations a and B is 315 kilometers
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According to the theory of plate tectonics, the following mountains, islands and oceans have common causes () A. Himalayas and RI Ben Islands B. Himalayas and Red Sea C. Ural Mountains and the Atlantic D. Red Sea and Indian Ocean
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