SOLUTION: I need to factor x2-6x-16=0. What I have is (x-4),(x-4) or (x-2), (x-8) as my answers. I am having a hard time looking at the example in my book vs. what my teacher gave us for our

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I need to factor x2-6x-16=0. What I have is (x-4),(x-4) or (x-2), (x-8) as my answers. I am having a hard time looking at the example in my book vs. what my teacher gave us for our      Log On


   

Question 89904: I need to factor x2-6x-16=0. What I have is (x-4),(x-4) or (x-2), (x-8) as my answers. I am having a hard time looking at the example in my book vs. what my teacher gave us for our assignment.
Found 2 solutions by stanbon, albert:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
factor x^2-6x-16=0
(x-8)(x+2)=0
x=8 or x=-2
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Comment: You can always check your factoring results with FOIL:
(x-8)(x+2)
F: x^2
O: 2x
I: -8x
L:-16
Combine to get x^2-6x-16
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Cheers,
Stan H.

Answer by albert(7) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2-6x-16=0


Plus = P
Multiplication = M


Every quadract equation is = x^2-Px+M=0


P+=-b%2Fa+ and M+=+c%2Fa


x%5E2-6x-16=0

a=1, b=-6 and c=-16


P=-%28-6%29%2F1 --> P=6 and M=-16%2F1-->M=-16


x%5E2-Px%2BM=0 is x%5E2-%286%29x%2B%28-16%29=0


What numbers have the plus=6 and multiplication=-16 ?
Answer: -2 and 8


The factor of x%5E2-6x-16=0 is highlight%28%28x-8%29%28x%2B2%29=0%29


**See this lesson video:

Link Video Polynomials-and-rational-expressions
Cheers.