Question

Ве­ло­си­пе­дист за два часа до­е­хал от пунк­та А до пунк­та Б. За пер­вый час он про­ехал семь де­ся­тых пути, а за вто­рой час — остав­ши­е­ся 12 км. Сколь­ко ки­ло­мет­ров про­ехал ве­ло­си­пе­дист за пер­вый час? подскажите пожалуйста,очень нужно. желательно со всеми объяснениями и вычислениями точно расписаннымихотч устроит и без точности..​

Answer 1

Ответ:

28 км

Пошаговое объяснение:

S- весь путь

1-0,7=0,3

0,3S=12

S=12/0,3=40

40*0,7=28

Answer 2

Ответ:

Время от пункта А до пункта Б - 2 часа.

первый час - 7/10 пути.

второй час - 12 км

Пусть весь путь 1.

1) 1 - 7/10 = 3/10 пути второй час (12 км)

2) 12 : 3/10 = 12 * 10/3 = 4 * 10/1 = 40 (км) - весь путь.

3) 40 - 12 = 28 (км) - велосипедист проехал за первый час.

Ответ: 28 километров.

Пошаговое объяснение:

Answer 3

Calculation of the Distance Traveled in the First Hour

To find out how many kilometers the cyclist traveled in the first hour, we can set up an equation based on the given information.

Let's assume that the total distance from point A to point B is D kilometers.

According to the problem, the cyclist traveled seven-tenths (7/10) of the total distance in the first hour. Therefore, the distance traveled in the first hour can be represented as:

Distance in the first hour = (7/10) × D

Calculation of the Remaining Distance

The problem states that the cyclist traveled the remaining 12 kilometers in the second hour. Therefore, the remaining distance can be represented as:

Remaining distance = 12 kilometers

Solving the Equations

To find the value of D, we can set up an equation by equating the total distance to the sum of the distance traveled in the first hour and the remaining distance:

D = (7/10) × D + 12

Now, we can solve this equation to find the value of D.

Subtracting (7/10) × D from both sides of the equation, we get:

(3/10) × D = 12

To isolate D, we can multiply both sides of the equation by 10/3:

D = (12 × 10) / 3

Simplifying the equation, we find:

D = 40 kilometers

Calculation of the Distance Traveled in the First Hour (continued)

Now that we know the total distance is 40 kilometers, we can calculate the distance traveled in the first hour using the equation we derived earlier:

Distance in the first hour = (7/10) × D = (7/10) × 40 = 28 kilometers

Therefore, the cyclist traveled 28 kilometers in the first hour.

Please let me know if you need any further assistance!