+128408 1. If x + 2 is a factor, then x = -2 is a root
Using synthetic division
-2 [ 5 8 -7 - 6 ]
-10 4 6
____________
5 -2 -3 0
Since we get 0 as a remainder, then -2 is a root and (x + 2) is a factor
2. Likewise....if (x + 1) is a factor and - 1 is a root.....so...
-1 [ 5 8 -7 - 6 ]
-5 -3 10
______________
5 3 -10 4
Since the remainder is not = 0, then -1 is not a root .....so x + 1 is not a factor
