Cortez's workout plan involves a total of 65 minutes of running and swimming. he burns 11 calories per minute when running and 9
calories per minute when swimming. let r represent the amount of time he spends running. write an expression to represent the amount of calories that he burns.
The equation to model this would be 65 = 11r + 9s.
In this equation, we know that the total number he works is 65. We also know he burns 11 every time he runs for an hour. Therefore we can multiply 11 by r. We also know he burns 9 for every hour he spends swimming. Therefore we can multiply 9 by s.
When we put all three of these things together, we get 65 = 11r + 9s.