Answer:
Dekalb: 3500+40x = F
Sycamores : 12,040 - 100x = F
Explanation:
These expressions can be used to explain each population
X = number of years for both expression
F = Final population
Dekalb: 3500+40x = F
Sycamores : 12,040 - 100x = F
The current population if 3500 if no years have gone by, plug in the year of numbers for X to find final population after the amount of years.