Question

велосепедист ехал a ч со скоростью12км/ч и 2ч со скоростью 8км/ч.Сколько километров проехал велосипедист за это время? Составте выражение для решения задачи и найдите его значение при а=1;2;4.

Answer 1

Problem Statement

A cyclist travels at a speed of 12 km/h for a certain amount of time and then at a speed of 8 km/h for 2 hours. How many kilometers did the cyclist travel during this time?

Solution

To solve this problem, we can use the formula: distance = speed × time.

Let's break down the problem into two parts:

1. The cyclist travels at a speed of 12 km/h for a certain amount of time. - Let's denote the time for this part as t1. - The distance traveled during this time is given by distance1 = speed1 × t1, where speed1 = 12 km/h. 2. The cyclist travels at a speed of 8 km/h for 2 hours. - The distance traveled during this time is given by distance2 = speed2 × t2, where speed2 = 8 km/h and t2 = 2 hours.

To find the total distance traveled, we need to add the distances from both parts: total distance = distance1 + distance2.

Let's substitute the given values and calculate the total distance for different values of t1 (a = 1, 2, 4).

For a = 1: - distance1 = 12 km/h × t1 - distance2 = 8 km/h × 2 hours - total distance = distance1 + distance2

For a = 2: - distance1 = 12 km/h × t1 - distance2 = 8 km/h × 2 hours - total distance = distance1 + distance2

For a = 4: - distance1 = 12 km/h × t1 - distance2 = 8 km/h × 2 hours - total distance = distance1 + distance2

Let's calculate the total distance for each value of a:

For a = 1: - distance1 = 12 km/h × 1 hour = 12 km - distance2 = 8 km/h × 2 hours = 16 km - total distance = 12 km + 16 km = 28 km

For a = 2: - distance1 = 12 km/h × 2 hours = 24 km - distance2 = 8 km/h × 2 hours = 16 km - total distance = 24 km + 16 km = 40 km

For a = 4: - distance1 = 12 km/h × 4 hours = 48 km - distance2 = 8 km/h × 2 hours = 16 km - total distance = 48 km + 16 km = 64 km

Therefore, the cyclist traveled: - 28 km for a = 1 - 40 km for a = 2 - 64 km for a = 4.

Please let me know if I can help you with anything else.