Question

ПОМОГИТЕ, не могу решить !!!ПервыйПОМОГИТЕ, не могу решить !!!Первый участок пути мотоциклист ехал со скоростью 42 км\ч, а второй- со скоростью 30 км\ч. всего он проехал 129 км. За сколько времени мотоциклист проехал первый участок пути и за сколько второй, если на первый участок пути он затратил на 0,5 ч меньше, чем на второй?

Answer 1

Х - время за которое проехал 1 уч
х+0,5 - время за которое проехал 2 уч

42х+30(х+0,5)=129
42х+30х+15=129
72х=129-15
72х=114
х=114/72
х=1  7/12=1ч 35мин - время за которое проехал 1 уч

1ч 35мин +0,5ч=2ч 05мин - время за которое проехал 2 уч

Answer 2

Problem Analysis

The problem states that a motorcyclist traveled two segments of a route at different speeds. The first segment was covered at a speed of 42 km/h, and the second segment was covered at a speed of 30 km/h. The total distance traveled was 129 km. The motorcyclist took 0.5 hours less time on the first segment compared to the second segment. We need to find the time taken for each segment.

Solution

Let's assume that the time taken for the first segment is t hours. Since the motorcyclist took 0.5 hours less time on the first segment, the time taken for the second segment would be t + 0.5 hours.

We can use the formula distance = speed × time to calculate the distances covered in each segment.

The distance covered in the first segment is given by 42 km/h × t hours, and the distance covered in the second segment is given by 30 km/h × (t + 0.5) hours.

According to the problem, the total distance covered is 129 km. Therefore, we can set up the equation:

42t + 30(t + 0.5) = 129

Now, let's solve this equation to find the value of t.

Calculation

42t + 30(t + 0.5) = 129

42t + 30t + 15 = 129

72t + 15 = 129

72t = 129 - 15

72t = 114

t = 114 / 72

t ≈ 1.583

Answer

The motorcyclist took approximately 1.583 hours to cover the first segment of the route.

To find the time taken for the second segment, we can substitute the value of t into the expression t + 0.5:

t + 0.5 ≈ 1.583 + 0.5 ≈ 2.083

Therefore, the motorcyclist took approximately 2.083 hours to cover the second segment of the route.