Question

158. Реши задачи. Вычисли и запиши ответы 1) в первом мотке 88 м проволоки,А во фтором150 м такой же проволоки. За первый мотокзаплатили на 124 руб. меньше, чем за второй. Каковастоимость двух мотков проволоки?Ответ:2) Самолёт пролетел 3940 км со скоростью 985 км/ч.Затем он пролетел 1790 км со скоростью 895 км/ч.Сколько времени затратил самолёт на весь рейс?Ответ:3) Машина сначала проехала 455 км, а затем ещё260 км с постоянной скоростью. Сколько часов маши-на была в пути, если вторую часть пути она проеха-ла на 3 часа быстрее, чем первую?Ответ:​

Answer 1

Ответ

2 задача

Ответ 6 часов

Пошаговое объяснение

2) чтобы найти время необходтимо разделить расстояние на скорость, то есть 3940:985= 4 (ч); 1790:895= 2 (ч), 4+2=6(ч)

Answer 2

1) To find the cost of the two wire coils, we need to determine the cost per meter of wire. Let's assume the cost per meter of wire is x rubles.

For the first coil with 88 meters of wire, the cost would be 88x rubles. For the second coil with 150 meters of wire, the cost would be 150x rubles.

According to the problem, the cost of the first coil is 124 rubles less than the cost of the second coil. So we can set up the equation:

150x - 88x = 124

Simplifying the equation, we get:

62x = 124

Dividing both sides by 62, we find:

x = 2

Therefore, the cost per meter of wire is 2 rubles. To find the total cost of the two wire coils, we can substitute this value back into the equations:

For the first coil: 88 * 2 = 176 rubles For the second coil: 150 * 2 = 300 rubles

So, the total cost of the two wire coils is 176 + 300 = 476 rubles.

2) To find the total time taken for the entire flight, we need to calculate the time taken for each leg of the journey and then add them together.

For the first leg of the journey, the plane traveled 3940 km at a speed of 985 km/h. To find the time taken for this leg, we can use the formula:

Time = Distance / Speed

So, the time taken for the first leg is 3940 / 985 = 4 hours.

For the second leg of the journey, the plane traveled 1790 km at a speed of 895 km/h. Using the same formula, we find:

Time = Distance / Speed

So, the time taken for the second leg is 1790 / 895 = 2 hours.

To find the total time taken for the entire flight, we add the times for both legs:

4 hours + 2 hours = 6 hours.

Therefore, the plane took 6 hours for the entire flight.

3) Let's assume the constant speed of the car is x km/h.

For the first part of the journey, the car traveled 455 km. To find the time taken for this part, we can use the formula:

Time = Distance / Speed

So, the time taken for the first part is 455 / x hours.

For the second part of the journey, the car traveled 260 km. According to the problem, the car traveled this part of the journey 3 hours faster than the first part. So, the time taken for the second part is (455 / x) - 3 hours.

To find the total time taken for the entire journey, we add the times for both parts:

(455 / x) + ((455 / x) - 3) = 8

Simplifying the equation, we get:

910 / x - 3 = 8

Adding 3 to both sides, we find:

910 / x = 11

Cross-multiplying, we get:

11x = 910

Dividing both sides by 11, we find:

x = 82.73

Therefore, the constant speed of the car is approximately 82.73 km/h. To find the total time taken for the entire journey, we can substitute this value back into the equation:

(455 / 82.73) + ((455 / 82.73) - 3) = 8

Simplifying the equation, we find:

5.5 + 2.5 = 8

Therefore, the car was on the road for 8 hours.