Answer:
k = - 58
Explanation:
Since (x + 8) and (3x + 2) are factors of the polynomial it means that if either one of them is equated to zero and substituted into the polynomial will give us zero
Using x + 8
We have
x + 8 = 0
x = - 8
Substitute the value of x into the polynomial
- 6x³ - 55x² + kx - 16
That's
- 6(-8)³ - 55(-8)² + k(-8) - 16 = 0
-6(-512) - 55(64) - 8k - 16 = 0
Expand
3072 - 3520 - 8k - 16 = 0
Simplify
- 464 - 8k = 0
8k = -464
Divide both sides by 8
k = - 58
Hope this helps you