Final answer:
An equation to model the temperature of Summer's coffee cooling at a rate of 0.5° F per minute is y = 120 - 0.5x, where x is the number of minutes and y is the temperature in degrees Fahrenheit.
Step-by-step explanation:
The student is requesting an equation to represent the relationship between time and the temperature of a cooling cup of coffee. Since the coffee is cooling at a constant rate, this can be modeled with a linear equation. Starting with a coffee temperature of 120° F, which decreases by 0.5° F per minute, we can express the temperature (y) after a certain number of minutes (x) with the equation y = 120 - 0.5x.