Question

Два грузовика выехали одновременно из двух городов навстречу друг другу,расстояние между которыми 756 км.Один из них проезжал в час на 9 км больше другого.Через 12ч они встретились.Сколько нужно каждому грузовику,чтобы проехать всё расстояние между этими городами?

Answer 1

Формула расстояние = скорость/время 
1) скорость 1 = 63 км/ч
    скорость 2 = 63+9 = 72 км/ч 
формула время = расстояние/скорость
2) время 1 = 756/72 = 10,5 ч
    время 2 = 756/63 = 12 ч

Answer 2

Problem Analysis

Two trucks start from different cities and travel towards each other. The distance between the cities is 756 km. One truck travels 9 km/h faster than the other. After 12 hours, they meet. We need to find the speed of each truck.

Solution

Let's assume the speed of the slower truck is x km/h. Then the speed of the faster truck would be x + 9 km/h.

To find the distance traveled by each truck, we can use the formula distance = speed × time.

For the slower truck: - Speed = x km/h - Time = 12 hours - Distance = x × 12 km

For the faster truck: - Speed = x + 9 km/h - Time = 12 hours - Distance = (x + 9) × 12 km

Since they meet after 12 hours, the sum of the distances traveled by both trucks should be equal to the total distance between the cities, which is 756 km.

So, we can set up the following equation:

x × 12 + (x + 9) × 12 = 756

Now, let's solve this equation to find the value of x.

Calculation

12x + 12(x + 9) = 756

Simplifying the equation: 12x + 12x + 108 = 756 24x + 108 = 756

Subtracting 108 from both sides: 24x = 648

Dividing both sides by 24: x = 27

Now that we have the value of x, we can find the speed of each truck.

For the slower truck: Speed = x = 27 km/h

For the faster truck: Speed = x + 9 = 27 + 9 = 36 km/h

Therefore, the slower truck needs to travel at a speed of 27 km/h, and the faster truck needs to travel at a speed of 36 km/h in order to cover the entire distance between the cities.

Answer

To cover the entire distance between the cities, the slower truck needs to travel at a speed of 27 km/h, and the faster truck needs to travel at a speed of 36 km/h.

Note: The answer provided is based on the information given in the problem statement and the calculations performed.