Question

PLEASE PLEASE HELP ME!!!

Julio and Deion steer dive boats for different scuba-diving companies. They can stay in radio communication with each other for up to 18 mi. Julio leaves a popular coral reef 15 min before Deion does and steers his boat north at an average speed of 20 mph. When Deion leaves the reef, he steers his boat south at an average speed of 15 mph.


Let j equal the number of hours Julio has been traveling and let d represent the number of hours Deion has been traveling.


The equation j−d= 0.25 represents the difference in the number of hours Julio and Deion have been traveling.


The equation 20j+15d=18 shows the distance between the boats when they fall out of communication with each other


Solve the system formed by these equations.


How many hours after Julio left the reef will he and Deion fall out of communication with each other?

Answer 1

• Julio and Dion will fall out of communication 0.62 hours after Julio left the reef.

Step-by-step explanation:

1. System of equations (given):

`1)j-d=0.25\\\\ 2)20j+15d=18`

2. Solution:

i) Multiply equation 1) by 15:

`3)15j-15d=3.75\\\\ 2)20j+15d=18`

ii) Add equations 3) and 4):

`5)15j+20j=3.75+18\\ \\ 35j=21.75`

iii) Divide by 35:

`j=21.75/35=0.6214`

The variable j is equal to the number of hours Julio has been traveling, hence it is 0.62 hours.