Which of the following formulas correctly expresses the relationship between Celsius and Fahrenheit?

The formula that correctly expresses the relationship between Celsius and Fahrenheit is represented by the equation where Fahrenheit is equal to nine-fifths of the Celsius temperature plus 32. This reflects the established conversion between these two temperature scales, acknowledging that 32 degrees Fahrenheit is the freezing point of water (0 degrees Celsius), and that each degree Celsius corresponds to an increase of 1.8 degrees Fahrenheit.

Celsius and Fahrenheit have different zero points and increments, making it essential to maintain both the conversion factor (9/5) and the adjustment (the addition of 32) accurate. This accurate relationship reflects how a temperature measured in Celsius can be directly converted to its corresponding Fahrenheit value through this formula.

The other options presented either misrepresent the relationship or incorrectly apply the conversions. For example, the first option suggests a disproportionate adjustment (5/9 C), while the last two options misalign the conversion factors or introduce unnecessary alterations to the original temperature. Understanding the correct formula is crucial for accurate temperature conversions in various applications, such as in heating, cooling, or scientific calculations.