Question

Из пункта А в пункт В со скоростью 12 километров час выехал велосипедист,а через полчаса вслед за ним выехал другой велосипедист, проезжавший в час 14 километров и прибывший в пункт В одновременно с первым велосипедистом. Найдите расстояние между А и В. Пожалуйста!!!! Пожалуйста!!!! Пожалуйста!!!!))))

Answer 1

          1-й     2-й

S          x       x

V          12     14

t            12/x     14/x

t1 меньше t2 на 1/2ч

Уравнение:

12/x + 1/2 = 14/x

12/x + 1/2 - 14/x = 0

(24 + x - 28)/2x = 0

1) 2x не равно 0, след. x не равно 0

2) 24 + x - 28 = 0

x = 4, след. S=4км.

Ответ: 4км.

Answer 2

Problem Analysis

We are given that a cyclist travels from point A to point B at a speed of 12 kilometers per hour. After half an hour, another cyclist starts from point A and travels to point B at a speed of 14 kilometers per hour. Both cyclists arrive at point B simultaneously. We need to find the distance between points A and B.

Solution

Let's assume the distance between points A and B is d kilometers.

The first cyclist travels at a speed of 12 kilometers per hour and starts half an hour before the second cyclist. Therefore, the first cyclist travels for (0.5 + t) hours, where t is the time taken by the second cyclist to reach point B.

The second cyclist travels at a speed of 14 kilometers per hour and starts half an hour after the first cyclist. Therefore, the second cyclist travels for t hours.

Since both cyclists arrive at point B simultaneously, the total distance traveled by both cyclists is equal to the distance between points A and B.

Using the formula distance = speed × time, we can write the following equation:

(0.5 + t) × 12 + t × 14 = d

Simplifying the equation, we get:

6 + 12t + 14t = d

20t + 6 = d

Therefore, the distance between points A and B is 20t + 6 kilometers.

To find the value of t, we can solve the equation using the given information.

Calculation

Let's solve the equation to find the value of t:

20t + 6 = d

Since both cyclists arrive at point B simultaneously, the time taken by the second cyclist to reach point B is the same as the time taken by the first cyclist to travel from point A to point B.

Let's assume the time taken by both cyclists is t hours.

Substituting t into the equation, we get:

20t + 6 = d

Now, we need to find the value of t.

Answer

The distance between points A and B is 20t + 6 kilometers, where t is the time taken by both cyclists to travel from point A to point B.