SOLUTION: -x^2-x+12>0

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Question 871955: -x^2-x+12>0
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
The quadratic function for the left member is factorable and has a maximum value in the middle of the two roots. The function values will need to be positive BETWEEN the two roots in order for the function to be greater than zero.

-x%5E2-x%2B12
-1%28x%5E2%2Bx-12%29
-1%28x-3%29%28x%2B4%29
Roots are 3 and -4.

The solution to the inequality is -4%3Cx%3C3.
You could check any point in each of the three intervals, if you were not sure.