The first part of a trip driving at 40 mph was 15 miles longer and took 30 minutes longer than the second part of the trip driving at 50 mph. What I'd the distance traveled?

Step-by-step explanation:

Let assume that both trip occured at constant speed. Then, the definition of speed as the ratio of travelled distance to time is used in terms of the statement:

First trip:

Second trip:

After some algebraic handling, the following linear system is created:

The solution of the linear system is:

The distance travelled in both trips is:

answer: 298143

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional