SOLUTION: Hello. I'm trying to factor out 28-13x-6x^2. I believe that I'm suppose to change the order to -6x^2-13x+28, but I'm not sure what to do next.

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Hello. I'm trying to factor out 28-13x-6x^2. I believe that I'm suppose to change the order to -6x^2-13x+28, but I'm not sure what to do next.      Log On


   



Question 271312: Hello. I'm trying to factor out 28-13x-6x^2. I believe that I'm suppose to change the order to -6x^2-13x+28, but I'm not sure what to do next.
Found 2 solutions by stanbon, LarissaRichardson:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Hello. I'm trying to factor out 28-13x-6x^2. I believe that I'm suppose to change the order to -6x^2-13x+28, but I'm not sure what to do next.
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-6x^2-13x+28
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This is what I do.
Using a graphing calculator I graph it to find where it
intersects with y=0
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I see the root is x = 4/3 so I know there is a factor of (3x-4)
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The other factor must be (-2x-7)
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Cheers,
Stan H.

Answer by LarissaRichardson(34) About Me  (Show Source):
You can put this solution on YOUR website!
Using Reverse Foil
Factor out the negative
6x^2+13x-28
It is really trial and error to find what times what will give you 6x^2.
You can try 1x and 6x, and 2x and 3x.
I chose:
(2x___)(3x____)
Next, figure out what multiplied by each other will give you 28 but added will give you 13 keeping in mind that you have the 3x and 2x to multiply using FOIL.
(2x-7)(3x+4)