Which of the following temperature conversion formulas is correct?

All the provided temperature conversion formulas are correct and can be used to convert between Fahrenheit and Celsius.

The first formula, which expresses Fahrenheit in terms of Celsius, is widely used and can be rearranged to produce the second formula. When you take the Celsius temperature and multiply it by 1.8 and then add 32, you directly convert it to Fahrenheit.

The third formula inversely converts Fahrenheit to Celsius. It provides a method for determining the Celsius temperature by taking the Fahrenheit temperature, subtracting 32, and then multiplying by 5/9, which is equivalent to dividing by 1.8.

Since all three formulas accurately reflect the relationships between Fahrenheit and Celsius, selecting the option that states "All of the above" is appropriate as they all are valid and correctly represent the temperature conversion process. Understanding these relationships is essential for anyone working with temperature-sensitive equipment, such as boilers, where precise temperature readings are crucial for operation and safety.