Question 982439
Same as synthetic division to check the roots  -3  for the polynomial function 2x^3+x^2-13x+6.


If remainder is 0, then -3 is a root and x+3 is a factor.  That's what the Factor Theorem means.



-3________|______2______1_______-13_______6
__________|
__________|____________-6_______15________-6
__________|_____________________________________
________________2_____-5________2________0


Remainder IS zero, so x+3 is a factor of the given polynomial function.