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?

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.

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

image result for what is another name for consecutive interior angles? ​

when two lines are crossed by another line (called the transversal): the pairs of angles on one side of the transversal but inside the two lines are called consecutive interior angles. in this example, these are consecutive interior angles: d and f.

step-by-step explanation:

sas (side angle side)

aa(angle angle)

sss(side side side)

sas you have to find two sides with an angle in between

aa you find two angles because it will always add up to 180

sss find all sides

step-by-step explanation: