Question

For the first 80 miles of her road trip, Lina travels 10 miles/hour slower than she did for the remaining 50 miles of her trip. If s represents Lina’s speed during the first part of her trip, which expressions represent the total time of her trip in hours?.

Answer 1

The expressions represent the total time of her trip in hours is$\rm \dfrac{80}{s} + \dfrac{50}{s+10}$.

Given that,

For the first 80 miles of her road trip, Lina travels 10 miles/hour slower than she did for the remaining 50 miles of her trip.

It represents Lina's  speed during the first part of her trip.

We have to determine,

Which expressions represent the total time of her trip in hours?

According to the question,

Let the speed traveled during the first part of the trip be "s".

The formula for calculating the distance is expressed as:

$\rm Distance = Speed \times Time$

For the first part of the journey:

Distance = 80 miles

Time = $\rm t_1$

And Speed = s

Substitute all the values in the formula,

$\rm Distance = Speed \times Time\\\\80 = s \times t_1\\\\ t_1= \dfrac{80}{s}$

For the second part of the trip;

Distance traveled = 50 miles

Speed = s + 10 (10miles/hour faster than the first part of the trip)

time = $\rm t_2$

Substitute all the values in the formula,

$\rm Distance = Speed \times Time\\\\50 = (s+10) \times t_2\\\\ t_2 = \dfrac{50}{s+10}$

Therefore,

Adding both the time to represent the total time of her trip in hours,

$\rm = t_1 +t_2 \\\\ = \dfrac{80}{s} + \dfrac{50}{s+10}$

Hence, The required expressions represent the total time of her trip in hours is$\rm \dfrac{80}{s} + \dfrac{50}{s+10}$.

For more details refer to the link given below.

brainly.com/question/21043759