Answer:
a = 5
Explanation:
According to the factor theorem, if x + 2 is a factor, then by dividing the polynomial by the binomial, we are meant not to have a remainder
In this case, the remainder would be zero
So, if we set the binomial equals zero and substitute the x-value into the polynomial, we are supposed to have 0
So we have this as;
x + 2 = 0
x = -2
-2^3 -2(-2)^2 -2(a) + 6 = 0
-8-8-2a + 6 = 0
-16 + 2a + 6 = 0
2a -10 = 0
2a = 10
a = 10/2
a = 5