SOLUTION: factor each trinomial using trail and error.15x^2-x-2

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Question 15507: factor each trinomial using trail and error.15x^2-x-2
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Factoring trinomials can entail a lot of educated guess-and-check work.
Factor:
15x%5E2+-+x+-+2 What are the possible factors of the x%5E2 term?
1) (15x)(x) or (-15x)(-x)
2) (5x)(3x) or (-5x)(-3x)
What are the possible factors of the constant term?
1) (1)(-2) or (-1)(2)
What combintation will give the x-term coefficient of -1?
1) (3)(-2) + (5)(1) This looks promising!
2) (-3)(2) + (5)(1) This won't do because you need to get a -2 as a constant term.
So, try:
%285x+-+2%29%283x+%2B+1%29 Check it out using FOIL.
%285x+-+2%29%283x+%2B+1%29+=+15x%5E2+%2B+5x+-+6x+-+2 = 15x%5E2+-x+-2