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 srepresents Lina's
speed during the first part of her trip, which expressions represent the total time of her trip in hours?
( The picture are the answer choices!!!)

For the first 80 miles of her road trip Lina travels 10 mileshour slower than she did for the remaining 50 miles of her trip If srepresents Linas speed during t class=

Respuesta :

Answer:

Option (5)

Step-by-step explanation:

Lina's speed during the first part of the trip = s miles per hour

If she travels initial 80 miles on this trip with this speed, time taken to cover the distance [tex]t_1=\frac{\text{Distance}}{\text{Speed}}=\frac{80}{s}[/tex] hours

Now speed at which she traveled remaining 50 miles = (s + 10) miles per hour

So the time spent to cover this distance  [tex]t_2=\frac{50}{s+10}[/tex] hours

Total time for the complete trip = [tex]t_1+t_2[/tex] = [tex]\frac{80}{s}+\frac{50}{s+10}[/tex]

= [tex]\frac{80(s+10)+50s}{s(s+10)}[/tex]

= [tex]\frac{80s+800+50s}{s(s+10)}[/tex]

= [tex]\frac{130s+800}{s(s+10)}[/tex]

Therefore, Option (5) will be the answer.

Option C is correct. The expressions that represent the total time of her trip in hours is [tex]t_1 + t_2 = \frac{80}{s} +\frac{50}{s+10} \\[/tex]

Let the speed travelled during the first part of the trip be "s"

The formula for calculating the distance is expressed as:

[tex]distance=speed\times time[/tex]

For the first part of the journey:

distance = 80miles

time = t₁

Speed = s

Substitute the given parameters into the formula:

[tex]80 = st_1\\t_1=\frac{80}{s}[/tex]........................................... 1

For the second part of the trip;

Distance travelled = 5 miles

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

time = t₂

Get the time  t₂

[tex]50=(s+10)t_2\\t_2=\frac{50}{s+10}[/tex]

Adding both times taken to get the total time of her trip in hours.

[tex]t_1 + t_2 = \frac{80}{s} +\frac{50}{s+10} \\[/tex]

Hence the expression that represent the total time of her trip in hours is [tex]t_1 + t_2 = \frac{80}{s} +\frac{50}{s+10} \\[/tex]

Learn more here: https://brainly.com/question/8085089