Question

Из пунктов а и в, расстояние между которыми 280 км, вышли два автомобиля. Если автомобили будут двигаться на встречу друг другу, то втсреча произойдет через 2 часа. Если же они будут двигаться в одном направлении, то автомобиль, вышедший из а, догонит автомобиль из в, через 14 часов. Какова скорость каждого автомобиля?

Answer 1

1. 14*2=28 2 280:28=10 km/ч скорость 1 авто из а 3 280:10= 28км/ч скорость авто из б

Answer 2

X-скорость первого автомобиля, y-скорость второго автомобиля,7(140-y)-7y=140980-7y-7y=14014y=840y=60x=80
вот решение

Answer 3

Problem Analysis

We have two cars, A and B, that start from points A and B, respectively. The distance between points A and B is 280 km. If the cars move towards each other, they will meet after 2 hours. If they move in the same direction, the car that started from point A will catch up to the car that started from point B after 14 hours. We need to find the speed of each car.

Solution

Let's assume the speed of car A is x km/h and the speed of car B is y km/h.

When the cars move towards each other, their combined speed is the sum of their individual speeds. The time it takes for them to meet is given as 2 hours. Therefore, the equation is:

280 km = (x + y) km/h * 2 hours When the cars move in the same direction, the relative speed is the difference between their speeds. The time it takes for car A to catch up to car B is given as 14 hours. Therefore, the equation is:

280 km = (x - y) km/h * 14 hours We now have a system of two equations with two unknowns. We can solve this system of equations to find the values of x and y.

Solving the System of Equations

Let's solve the system of equations and to find the values of x and y.

From equation we can rewrite it as:

280 km = 2x km/h + 2y km/h

Simplifying, we get:

140 km = x km/h + y km/h From equation we can rewrite it as:

280 km = 14x km/h - 14y km/h

Simplifying, we get:

20 km = x km/h - y km/h We now have a system of two equations:

140 km = x km/h + y km/h 20 km = x km/h - y km/h We can solve this system of equations using any method, such as substitution or elimination. Let's use the elimination method.

Adding equations and we get:

160 km = 2x km/h

Dividing both sides by 2, we get:

80 km = x km/h Substituting the value of x from equation into equation we get:

140 km = 80 km/h + y km/h

Simplifying, we get:

60 km = y km/h Therefore, the speed of car A is 80 km/h and the speed of car B is 60 km/h.

Answer

The speed of car A is 80 km/h and the speed of car B is 60 km/h.