We are given polynomial: .
We need to explain why the binomial (x + 2) IS a factor of this polynomial expression and why the binomial (x + 1) IS NOT a factor of this polynomial expression.
Let us set first factor equal to 0 and solve for x.
x+2=0
x=-2.
Plugging x=-2 in given polynomial, we get
<em>Because x=-2 gives 0 on plugging in given polynomial, so it's factor of given polynomial expression.</em>
Now, let us check second factor x+1=0
x=-1.
Plugging x=-1 in given polynomial, we get
=-5+8+7-6.
= -4.
<em>Because x=-1 doesn't gives 0 on plugging in given polynomial, so it's not a factor of given polynomial expression.</em>