please help i'm stuck :,)

Jacob and Sophia are in a running club and record how long it takes them to run a 5-kilometer race. Jacob's time was 4 minutes under the average time of the running club. The difference between Jacob's time and Sophia's time is 10 minutes. The possible times of Sophia's run are ____ minutes below the average or ____ minutes above the average.

Respuesta :

Answer:

14 minutes below or 6 minutes above

Step-by-step explanation:

Let's say Sophia's time was 10 minutes WORSE

4 minutes below average- 10 minutes= 14 minutes below average

Let's say Sophia's time was ten minutes BETTER

4 minutes below average + 10 minutes= 6 minutes above average.

Hope this helps!

Answers:

14 minutes below the average

6 minutes above the average

=====================================================

Let A = average running time

Jacob's time was 4 minutes under the average, so his time is A-4 minutes. Whatever A is, subtract off 4, and you'll get Jacob's time.

Sophia and Jacob have a difference of 10 minutes. If J = Jacob's time and S = sophia's time, then S-J = 10 or J-S = 10 depending on who has the larger time.

We can use absolute value to ensure that whatever we pick (S-J or J-S) will be positive. So |S-J| = 10. Recall that absolute value represents distance on a number line. Negative distance isn't possible.

-------------

Let's plug in J = A-4 and solve for S

|S-J| = 10

|S - ( J )| = 10

|S - (A-4)|

|S-A+4| = 10

S-A+4 = 10  or  S-A+4 = -10

S-A = 10-4  or  S-A = -10-4

S-A = 6  or  S-A = -14

S = A+6 or S = A-14

The equation S = A+6 shows Sophia is 6 minutes above the average

The equation S = A-14 shows Sophia is 14 minutes below the average

-------------

Let's pick some number for A that is over 14 minutes. Let's say the average running time is A = 20 minutes.

If A = 20, then Jacob's time is J = A-4 = 20-4 = 16

If the average running time is 20 minutes, then Jacob ran for 16 minutes.

If we subtract 10 from this, then J-10 = 16-10 = 6 is one possible time for Sophia. Notice how this is 14 minutes below the average (20-14 = 6)

If we add 10 to Jacob's time, then J+10 = 16+10 = 26, which is 6 minutes overage the average (20+6 = 26)

This is one numeric example, but you could use any value of A that you want as long as it's larger than 14. The reason A has to be larger than 14 is to ensure that Sophia's lower time value (A-14) is not negative. Having a time of zero is not feasible either.

ACCESS MORE