Question

9 Реши задачу с помощью уравнения. Расстояние между посёлком и городом — 81 км. Из них одно- временно навстречу друг другу выехали два велосипедиста и встретились через 3 часа. Скорость велосипедиста, выехавше- го из города, — 12 км/ч. Какова скорость другого велосипедиста?​

Answer 1

Ответ: Скорость 2-го велосипедиста равна 15 км/ч

Пошаговое объяснение: Пусть скорость 2-го велосипедиста равна Х, суммарная скорость сближения 12+Х км/ч и она равна 81/3=27 км/ч Итого 12+Х=27. Х=27-12=15

Answer 2

Problem Analysis

We are given that the distance between a village and a city is 81 km. Two cyclists start from opposite ends and meet after 3 hours. The speed of one cyclist, who starts from the city, is 12 km/h. We need to find the speed of the other cyclist.

Solution

Let's assume the speed of the other cyclist is x km/h.

Since both cyclists meet after 3 hours, we can use the formula: distance = speed × time.

The distance covered by the first cyclist, who starts from the city, is 12 km/h × 3 hours = 36 km.

The distance covered by the second cyclist, who starts from the village, is also 36 km.

The total distance between the village and the city is 81 km. Therefore, the remaining distance covered by the second cyclist is 81 km - 36 km = 45 km.

We can set up the following equation to find the speed of the second cyclist:

45 km = x km/h × 3 hours

To solve for x, we divide both sides of the equation by 3:

45 km / 3 hours = x km/h

Simplifying, we find:

15 km/h = x

Therefore, the speed of the second cyclist is 15 km/h.

Answer

The speed of the second cyclist is 15 km/h.