Question

In order to join a voice lesson class you pay a 1,500 pesos fee, then 500 for each class you go to what is the average cost per class graph the function to show whether it form a straight line or a curve

Answer 1

Let $x=$ the number of classes.

The total cost for $x$ classes is

$$C(x)=1500+500x, x\in \N$$

The average cost per class is

$$C_{ave}=\begin{cases} 1500 &x=0 \\ \dfrac{1500}{x}+500 &x\in\Z^+ \end{cases}$$