Monica teaches piano lessons. She charges $35 for a lesson. If the input is the number of lessons Monica teaches, write a rule for the amount she earns in dollars?

Let's take the "input", the "x" value in this sense, as the number of lessons Monica teaches.

So if it's $35 for each lesson, f(x)=$35x

To write a rule for the amount Monica earns based on the number of lessons she teaches, we can use the concept of a linear function. In this case, the amount Monica earns is directly proportional to the number of lessons she teaches.

Let's define some variables:
- Let "x" represent the number of lessons Monica teaches.
- Let "E" represent the amount Monica earns for teaching x lessons.

The given information states that Monica charges $35 for each lesson. Therefore, we can derive the rule as follows:

E = 35x

This means that the amount Monica earns, "E," is equal to 35 times the number of lessons she teaches, represented by "x."