Question

Расстояние между пунктами А и В автомобиль проехал за 1,2 часа, а автобус за 2,1 часа. Найдите скорость каждой машины, если автомобиль двигался на30 км/ч быстрее чем автобус.Тема: решение задач на составление уравнений.

Answer 1

Пусть х км/ч скорость автобуса, тогда скорость автомобиля х+30 км/ч. Расстояние которое проехал автобус 2,1х км равно расстоянию которое проехал автомобиль 1,2(х+30). Составим уравнение: 2,1х=1,2(х+30), 2,1х-1,2х=36, 0,9х=36, х=40 км/ч скорость автобуса, 40+30=70 км/ч скорость автомобиля.

Answer 2

Скорость автобуса - х, скорость авто - х+301,2*(х+30)=2,1*х1,2х+36=2,1х0,9х=36х=40скорость автобуса - 40 км/ч, авто - 70 км/ч. 

Answer 3

Problem Analysis

We are given that a car and a bus traveled from point A to point B in different amounts of time. The car took 1.2 hours, while the bus took 2.1 hours. We are also given that the car was traveling 30 km/h faster than the bus. We need to find the speed of each vehicle.

Solution

Let's assume the speed of the bus is x km/h. Since the car was traveling 30 km/h faster than the bus, the speed of the car would be x + 30 km/h.

We can use the formula speed = distance / time to find the distance traveled by each vehicle.

For the car: - Speed = x + 30 km/h - Time = 1.2 hours - Distance = Speed * Time = (x + 30) * 1.2 km

For the bus: - Speed = x km/h - Time = 2.1 hours - Distance = Speed * Time = (x) * 2.1 km

Since both vehicles traveled the same distance from point A to point B, we can set up the equation:

(x + 30) * 1.2 = (x) * 2.1

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

Calculation

Expanding the equation:

1.2x + 36 = 2.1x

Rearranging the equation:

2.1x - 1.2x = 36

0.9x = 36

Dividing both sides by 0.9:

x = 36 / 0.9

x = 40

So, the speed of the bus is 40 km/h.

Now, let's find the speed of the car:

Speed of the car = x + 30 = 40 + 30 = 70 km/h.

Answer

Therefore, the speed of the bus is 40 km/h, and the speed of the car is 70 km/h.