Number 4.
Four is a linear, it is the first composite number, as well as the first non-prime number (after 1 of course).
Answer:
x+2 is a factor of 
Step-by-step explanation:
To check: If (x+2) is a a factor of the polynomial 
We need to check if x = -2 is the FACTOR of the given polynomial.
⇒ To show: f (-2) = 0
Now

Since, f(-2) = 0
⇒ -2 is the ROOT of the Polynomial f(x).
⇒(x +2) is the factor of the given polynomial.
Hence, x+2 is a factor of 
The answer you are looking for is: -15.
I hope this helps.
It can't be simplified, it is already in its lowest term