Writing Equations to Model Relationships

Jada plans to serve milk and healthy cookies for a book club meeting. She is preparing 12 ounces of milk and 4 cookies per person. Including herself, there are 15 people in the club. A package of cookies contains 24 cookies and costs $4.50.

A 1-gallon jug of milk contains 128 ounces and costs $3. Let n represent number of people in the club, m represent the ounces of milk, c represent the number of cookies, and b represent Jada's budget in dollars.

Select all of the equations that could represent the quantities and constraints in this situation.

A student on the track team runs 45 minutes each day as a part of her training. She begins her workout by running at a constant rate of 8 miles per hour for a minutes, then slows to a constant rate of 7.5 miles per hour for b minutes.

Which equation describes the relationship between the distance she runs in miles, D, and her running speed, in miles per hour?

Elena bikes 20 minutes each day for exercise.

Write an equation to describe the relationship between her distance in miles, D, and her biking speed, in miles per hour, when she bikes:

at a constant speed of 13 miles per hour for the entire 20 minutes (Hint what fraction of an hour is 20mins)

Elena bikes 20 minutes each day for exercise.

Write an equation to describe the relationship between her distance in miles, D, and her biking speed, in miles per hour, when she bikes:

at a constant speed of 15 miles per hour for the first 5 minutes, then at 12 miles per hour for the last 15 minutes (Hint what fraction of an hour is 5 mins and 15 mins?)