[tex]f(x)=[/tex][tex]Min(800+(20\times x),1600) \times Max(300-(5\times x),0)[/tex]
Step-by-step explanation:
Initial the number of apartments rented are [tex]800[/tex]
Initial rent for each apartment is $[tex]300[/tex]
Given that the number of $5 decreases is [tex]x[/tex]
Number of apartments rented for [tex]x[/tex] number of decreases=[tex]Min(800+(20\times x),1600)[/tex]
This is because the maximum number of apartments are 1600.
Rent for each apartment for [tex]x[/tex] number of decreases=[tex]Max(300-(5\times x),0)[/tex]
This is because the rent cannot be negative.
So, the function for total rental income=[tex]Min(800+(20\times x),1600) \times Max(300-(5\times x),0)[/tex]