B. -3
The value of a for given polynomial is -3
<h3>
Explanation:</h3>
<em>Factor theorem for polynomials,</em>
<u><em>If (x-c) is a factor of polynomial f(x), then f(c)=0</em></u>
Given: x+a is a factor of polynomial 
Let 
By Factor theorem, since x+a is a factor of f(x),
![(x+a)=[x-(-a)]\\So,\ f(-a)=0](https://tex.z-dn.net/?f=%28x%2Ba%29%3D%5Bx-%28-a%29%5D%5C%5CSo%2C%5C%20f%28-a%29%3D0)
Substituting 
in f(x)=0, we get
![f(x) = 4x^3-13x^2-ax = 0\\f(-a)= [4(-a)^3]-[13(-a)^2]-[a(-a)] = 0\\(-4a^3-13a^2+a^2)=0\\(-4a^3-12a^2)=0\\-4a^3=12a^2\\\frac{a^3}{a^2} =\frac{12}{-4} \\\\a=(-3)](https://tex.z-dn.net/?f=f%28x%29%20%3D%204x%5E3-13x%5E2-ax%20%3D%200%5C%5Cf%28-a%29%3D%20%5B4%28-a%29%5E3%5D-%5B13%28-a%29%5E2%5D-%5Ba%28-a%29%5D%20%3D%200%5C%5C%28-4a%5E3-13a%5E2%2Ba%5E2%29%3D0%5C%5C%28-4a%5E3-12a%5E2%29%3D0%5C%5C-4a%5E3%3D12a%5E2%5C%5C%5Cfrac%7Ba%5E3%7D%7Ba%5E2%7D%20%3D%5Cfrac%7B12%7D%7B-4%7D%20%5C%5C%5C%5Ca%3D%28-3%29)
Therefore, value of a is (-3)
The dust bowl moving eastward. A lot of poor people lived in the W. and all the middle class lived in the East. Once the bowl moved E. it really screwed the middle class over worst than the poor because they didn't know what to do when that happened.
The American civil war was caused not by slavery but by economic factors
Answer:
I’m not entirely sure but I would say the answer to this question would be Marquis De LaFayette
Explanation:
