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It is known that a's speed is 45 km / h, and B's speed is 30 km / h. After all, B's speed immediately returns to meet B's. So, how much did a's speed go from starting to meeting? It's a linear equation of one variable
Let's set out for X hours
45x+30x=90*2
The solution is x = 12 / 5
45x=108
That is to say, the first athlete walked a total of 108 kilometers from the departure to the meeting
A car from city a to city B was supposed to arrive in five hours. If the speed is increased by 25%, how many hours will it arrive in advance
1÷﹙1＋25％﹚＝4/5
5 × 4 / 5 = 4 hours
A car drove from city a to city B. It was planned to arrive in 5 hours, but it actually arrived in city B in 4 hours. How much faster was the actual speed than the plan?
A. (5-4) △ 4 × 100%
B. (1 / 4-1 / 5) △ 1 / 5 × 100%
C. (1 / 4-1 / 5) △ 1 / 4 × 100%
B. (1 / 4-1 / 5) △ 1 / 5 × 100%
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