Mathematics, 27.11.2019 02:31 sdolina5

Alex was biking along a 48 mile trail. first half of the time he was biking twice as fast as the second half of the time. if he spent 4 hours on the road, how fast was he biking at first?

Answers: 1

Show answers

Answers

Answer from: 916837

The speed in the first part is 16 mph.

Step-by-step explanation:

The total distance is 48 miles. The total time is 4 hours.

In the second part of the trip, he was traveling at speed s for distance d for 2 hours.

In the first part of the trip he was traveling at twice the speed, or 2s, for distance 48 - d, for 2 hours.

speed = distance/time

distance = speed * time

First part of trip:

48 - d = 2s * 2

d + 4s = 48 Equation 1

Second part of the trip:

d = s * 2

d = 2s Equation 2

Equations 1 and 2 form a system of equations in two unknowns, d and s.

d + 4s = 48

d = 2s

Substitute 2s for d in equation 1.

2s + 4s = 48

6s = 48

s = 8

The speed in the second part is 8 mph.

The speed in the first part is 2s = 2(8) = 16.

The speed in the first part is 16 mph.

Check:

d = 2s = 2(8) = 16

48 - d = 48 - 16 = 32

The second part is 16 miles. The first part is 32 miles.

16 miles at 8 mph takes 2 hours.

32 miles at 16 mph takes 2 hours.

2 hours + 2 hours = 4 hours.

Our answer is correct.

The speed in the first part is 16 mph.

Answer from: charlettethomap7e9st

The speed in the first part is 16 mph.

Step-by-step explanation:

The total distance is 48 miles. The total time is 4 hours.

In the second part of the trip, he was traveling at speed s for distance d for 2 hours.

In the first part of the trip he was traveling at twice the speed, or 2s, for distance 48 - d, for 2 hours.

speed = distance/time

distance = speed * time

First part of trip:

48 - d = 2s * 2

d + 4s = 48 Equation 1

Second part of the trip:

d = s * 2

d = 2s Equation 2

Equations 1 and 2 form a system of equations in two unknowns, d and s.

d + 4s = 48

d = 2s

Substitute 2s for d in equation 1.

2s + 4s = 48

6s = 48

s = 8

The speed in the second part is 8 mph.

The speed in the first part is 2s = 2(8) = 16.

The speed in the first part is 16 mph.

Check:

d = 2s = 2(8) = 16

48 - d = 48 - 16 = 32

The second part is 16 miles. The first part is 32 miles.

16 miles at 8 mph takes 2 hours.

32 miles at 16 mph takes 2 hours.

2 hours + 2 hours = 4 hours.

Our answer is correct.

The speed in the first part is 16 mph

Answer from: Quest

answer: hey there,

the answer you are looking for is a..

hope this you!

Answer from: Quest

fjfjfhdhdhdhjjdjdjdjdjjd thats the answers

step-by-step explanation:

Another question on Mathematics

Mathematics, 20.06.2019 18:04

Point $(x,y)$ is randomly picked from the rectangular region with vertices at $(0,,,2010),$ and $(0,2010)$. what is the probability that $x > 7y$? express your answer as a common fraction.

Answers: 1

Answer

Mathematics, 21.06.2019 18:40

Some boys and girls were asked if they had a pet. one third of the group were boys. there were 20 boys. 20% of the girls had a pet. boys with a pet : girls with a pet = 1 : 5 i need to know how many girls there are.

Answers: 3

Answer

Mathematics, 21.06.2019 19:50

Which inequality is equivalent to -3x < -12? x < 4 , x < -4 , x > 4, x > -4

Answers: 1

Answer

Mathematics, 21.06.2019 21:00

Isabel graphed the following system of equations. 2x – y = 6 y = -3x + 4 she came up with the solution (2,-2). what were the 3 steps she did to get that solution? (make sure they are in the correct order)

Answers: 2

Answer

You know the right answer?

Alex was biking along a 48 mile trail. first half of the time he was biking twice as fast as the sec...

Questions