Answer:
17.9
Step-by-step explanation:
You could use PEMDAS but you don't really need to because this is just adding an subtracting.
Answer:

Step-by-step explanation:
can also be written as 

Simply to 
-OTHER METHOD-
can be simplified to 

Answer:
See below.
Step-by-step explanation:
t represents time (probably years).
The population of bobcats can't be negative, so negative values in the range do not make sense.
The function is continuous, but you're probably only looking at discrete values.