Question 271296: x^2+2x-48=0
Answer by LarissaRichardson(34)   (Show Source):
You can put this solution on YOUR website! x^2+2x-48=0
You will need to use Reverse FOIL
A. Set your parenthesis (excuse the lines inside, if I don't do that it will look like this () which is confusing.)
(__)(__)
B.Now ask yourself, what multiplied by what will give you x^2? x multiplied by x will give you x^2.
When using FOIL, this would be the F in the word FOIL (First)
(x__)(x__)
C. Now ask yourself, what multiplied by what will give me -48 but added together will give me 2?
Answer: -6 multiplied by 8 will give me -48 and when you add -6+8 together you will get 2.
This step provides for the OIL in FOIL (outside, inside last)
(x-6)(x+8)=0
(If you foil that you will get your original equation.)
No set both equal to zero:
x-6=0 which is x=6
and
x+8=0 which is x=-8
So you have:
x=6 and x=-8
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