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The speed of a car driving from Tianjin to Beijing is out of proportion to the time it takes
A car travelling from Tianjin to Beijing is not in proportion to the time it takes
Because the distance is fixed, distance = speed x time
If the average speed of a car is 60 km / h from Tianjin to Beijing, which is 120 km away from Tianjin, the distance between the car and Tianjin is Y1 (km) and the travel time t
(h) And judge whether it is a linear function
2. Find the relationship between the distance Y2 (km) from Beijing and the driving time t (H), and determine the range of independent variables
1、
y1 = 60t ,
This is a positive proportional function and a linear function
2、
y2 = 120-60t ,
Because it takes 120 △ 60 = 2 hours for the car to travel from Tianjin to Beijing,
Therefore, the value range of independent variable is: 0 ≤ t ≤ 2
The time it takes for a car to travel from place a to place B at a constant speed is proportional to its speed
The time it takes for a car to travel from place a to place B at a constant speed is proportional to its speed
It should be inverse
It takes 8 hours for a car to go from place a to place B, and 6 hours to go back from place B to place a. the return time is shortened by ()% and the speed is increased by ()%
It takes 8 hours for a car to drive from a to B, and 6 hours to drive back from B to a. the return time is shortened by (25)%, and the speed is increased by (33.33)%
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