Final answer:
The correct equation to show the relationship between Fahrenheit and Celsius is C = 5/9(F - 32), which is the answer choice a. This equation is derived from the freezing and boiling points of water on both temperature scales.
Step-by-step explanation:
The relationship between degrees Fahrenheit and degrees Celsius can be represented by an equation of a line due to the linear nature of the temperature conversion. The freezing point of water is 0°C or 32°F, and the boiling point is 100°C or 212°F.
Given this information, the equation for converting Fahrenheit to Celsius is C = 5/9(F - 32). This equation indicates that for each increase in Fahrenheit, the Celsius temperature increases by 5/9 of this change. The option that correctly represents this relationship is a. C = 5/9(F - 32), as the others are either incorrectly formulated or represent the inverse relationship (from Celsius to Fahrenheit).