Answer:
converts Celsius to Fahrenheit.
converts Fahrenheit to Celsius.
Step-by-step explanation:
Write given data in the table

Let the expression for the function be

Note, that this equation is linear equation and it is well-known fact that the Celsius to Fahrenheit dependence is linear.
Substitute corresponding values into this expression:

Subtract these two equations:

Substitute it into the first equation:

So,

This is the function which converts Celsius to Fahrenheit.
And function
converts Fahrenheit to Celsius.