Question

Из пунктов А и Б навстречу друг другу одновременно вышли два пешехода. Скорость первого на 1 км/ч больше скорости второго, поэтому он прибыл в пункт Б на 1 час ранеше,чем второй в пункт А. Найдите скорости пешеходов ,если расстояние между пунктами АиБ равно 20 км.

Answer 1

Пусть скорость одного х км\час а другого х+1 км\час. Вычислим время 20\х час и 20\х+1 час . Один потратил времени на час больше, чем другой составим уравнение 20\х-20\х+1=1 получим х*х+х-20=0 х= -1+- корень из 81и делитьна 2. = -1+- 9делить на 2 х= -1+9\2= 4 х= -1-9\2= -10 не удовл. Значит скорость одного 4 км\час, а другого 5 км\час.

Answer 2

Problem Analysis

We are given that two pedestrians start walking towards each other simultaneously from points A and B. The first pedestrian's speed is 1 km/h faster than the second pedestrian. The first pedestrian arrives at point B 1 hour earlier than the second pedestrian arrives at point A. We need to find the speeds of the pedestrians given that the distance between points A and B is 20 km.

Solution

Let's assume the speed of the second pedestrian is x km/h. Then the speed of the first pedestrian would be x + 1 km/h.

We can use the formula distance = speed × time to calculate the time taken by each pedestrian to reach their respective points.

For the first pedestrian: - Distance = 20 km - Speed = x + 1 km/h - Time = 20 / (x + 1) hours

For the second pedestrian: - Distance = 20 km - Speed = x km/h - Time = 20 / x hours

According to the given information, the first pedestrian arrives at point B 1 hour earlier than the second pedestrian arrives at point A. So we can set up the equation:

20 / (x + 1) = 20 / x + 1

To solve this equation, we can cross-multiply and simplify:

20x = 20(x + 1) + x(x + 1)

Simplifying further:

20x = 20x + 20 + x^2 + x

Simplifying again:

0 = x^2 + 2x + 20

This is a quadratic equation. We can solve it by factoring or using the quadratic formula. Let's use the quadratic formula:

x = (-b ± √(b^2 - 4ac)) / (2a)

In this case, a = 1, b = 2, and c = 20. Substituting these values into the formula:

x = (-2 ± √(2^2 - 4 * 1 * 20)) / (2 * 1)

Simplifying further:

x = (-2 ± √(4 - 80)) / 2

x = (-2 ± √(-76)) / 2

Since the square root of a negative number is not a real number, there are no real solutions to this equation. This means that there is no valid solution for the speeds of the pedestrians given the given conditions.

Therefore, it is not possible to determine the speeds of the pedestrians based on the information provided.

Answer

Based on the given information, it is not possible to determine the speeds of the pedestrians.