Question

Велосипедист ехал 2 ч по просёлочный дороге и 1 ч по шоссе. Всего он проехал 28км .С какой скоростью велосипедист ехал по просёлочной дороге и с какой по шоссе ,если известно что его скорость по шоссе была на 4км/ ч больше ,чем скорость по просёлочной дороге?

Answer 1

пусть скорость по проселочной будет х, а по шоссе х+4.

скорость*время=расстояние

2х+1*(х+4)=28

2х+х+4=28

3х=24

х=8 - скорость по проселочной

8+4=12 - скорость по шоссе

 

Answer 2

пусть х км/- скорость велосипедиста по проселочной дороге, то по шоссе его скорость (х+4) км/ч, а всего он проехал 28 км. Составим уравнение

2*х+1(х+4)=28

2х+х+4=28

3х=24

х=8

Скорость по роселочной дороге 8 км/ч, то по шоссе скорость 8+4=12 км/ч

Answer 3

Problem Analysis

We are given that a cyclist traveled for 2 hours on a dirt road and 1 hour on a highway, covering a total distance of 28 km. We also know that the cyclist's speed on the highway was 4 km/h faster than their speed on the dirt road. We need to find the speeds of the cyclist on both the dirt road and the highway.

Solution

Let's assume the speed of the cyclist on the dirt road is x km/h. According to the given information, the speed on the highway is (x + 4) km/h.

To find the speeds, we can use the formula:

Speed = Distance / Time

Let's calculate the distances traveled on each road:

- Distance on the dirt road = Speed on the dirt road * Time on the dirt road = x km/h * 2 h = 2x km - Distance on the highway = Speed on the highway * Time on the highway = (x + 4) km/h * 1 h = x + 4 km

According to the problem, the total distance traveled is 28 km. Therefore, we can write the equation:

Distance on the dirt road + Distance on the highway = Total distance

Substituting the calculated distances, we have:

2x km + (x + 4) km = 28 km

Simplifying the equation:

3x + 4 = 28

3x = 24

x = 8

The speed on the dirt road is 8 km/h and the speed on the highway is (8 + 4) km/h = 12 km/h.

Therefore, the cyclist traveled at a speed of 8 km/h on the dirt road and 12 km/h on the highway.

Answer

The cyclist traveled at a speed of 8 km/h on the dirt road and 12 km/h on the highway.