To calculate the maximum value of the function, let's calculate the first derivative and equal it to zero, as following:
[tex]\begin{gathered} \frac{dR}{dx}=100-0.50x \\ \\ \Rightarrow100-0.50x=0 \end{gathered}[/tex]Solving for x :
[tex]\begin{gathered} 100-0.5x=0\rightarrow100=0.5x\rightarrow\frac{100}{0.5}=x \\ \Rightarrow x=200 \end{gathered}[/tex]Therefore, we can say that 200 rented villas produce the maximum revenue