Question

Экскурсанты за день прошли 19,6 км. С утра они шли 5 час(-а), а после обеда — ещё 3 час(-а). Сколько километров экскурсанты прошли утром, если после обеда их скорость снизилась на 2 км/ч. С какой скоростью шли экскурсанты утром? Экскурсанты утром прошли км со скоростью км/ч. Пожалуйста помогите с алгеброй

Answer 1

Ответ:

4х + 5(х+1) = 19,4

9х + 5 = 19,4

9х = 14,4 х = 1,6 км (скорость после обеда)

Утром скорость составила 1,6 + 1 = 2,7 км/ч.

Answer 2

19.6=5х+3(х-2)

19.6=5х+3х-6

25.6=8х

х=3.2(км/ч)—утром

3.2-2=1.2(км/ч)—после обеда

Answer 3

Problem Analysis

The excursionists walked a total of 19.6 km in a day. They walked for 5 hours in the morning and an additional 3 hours after lunch. The speed of the excursionists decreased by 2 km/h after lunch. We need to find out how many kilometers the excursionists walked in the morning and at what speed they were walking.

Solution

Let's assume that the speed of the excursionists in the morning was x km/h. After lunch, their speed decreased by 2 km/h, so their speed in the afternoon was (x - 2) km/h.

We know that the excursionists walked a total of 19.6 km in the day. We can set up the following equation to represent this:

Distance walked in the morning + Distance walked in the afternoon = Total distance walked

Let's calculate the distance walked in the morning and the speed at which the excursionists were walking.

Calculation

Distance walked in the morning = Speed × Time

The excursionists walked for 5 hours in the morning, so the distance walked in the morning can be calculated as:

Distance walked in the morning = x km/h × 5 h

The excursionists walked for 3 hours in the afternoon, so the distance walked in the afternoon can be calculated as:

Distance walked in the afternoon = (x - 2) km/h × 3 h

According to the problem, the total distance walked is 19.6 km. So we have the equation:

x km/h × 5 h + (x - 2) km/h × 3 h = 19.6 km

Now we can solve this equation to find the value of x and calculate the distance walked in the morning.

Solution

Let's solve the equation:

5x + 3(x - 2) = 19.6

Expanding and simplifying the equation:

5x + 3x - 6 = 19.6

8x - 6 = 19.6

8x = 25.6

x = 3.2

So, the speed of the excursionists in the morning was 3.2 km/h.

Now, let's calculate the distance walked in the morning:

Distance walked in the morning = 3.2 km/h × 5 h = 16 km

Therefore, the excursionists walked 16 km in the morning at a speed of 3.2 km/h.

Answer

The excursionists walked 16 km in the morning at a speed of 3.2 km/h.