SOLUTION: 25 if x squared-x-6=0 then x is: A) -2 or 3 B) -1 or 6 C) 1 or -6 D) 2 or -3

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Question 69265: 25 if x squared-x-6=0 then x is: A) -2 or 3 B) -1 or 6 C) 1 or -6 D) 2 or -3
Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2-x-6=0 quadratic in standard form
A=1
B=-1
C=-6
By inspection, the factors are (x-3) and (x+2). Now how do I know this??? Well, when the quadratic equation has the A coefficient equal to 1, then the B coefficient is equal to the sum of the factors of the C coefficient. if the quadratic can be factored. What are the factors of -6??
-6*+1, +6*-1, +3*-2 and -3*+2-------------the sum of -3 and +2 is -1 and that's what we want.

%28x-3%29%28x%2B2%29=0
x=3
and
x=-2
The answer is A------------------------------------------------ans

Hope this helps---ptaylor