Question 333189: solve:
(x+4)(x-1)(x+2)>0
Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website!
Set each of the factors in the LHS equal to 0 and solve. That will give you three critical points, namely (-4,0), (-2, 0), and (1, 0).
These three points divide the  -axis into four intervals. Smaller than -4, between -4 and -2, between -2 and 1, and larger than 1.
Select 4 values, one from each interval, but don't select any of the critical points. Substitute each of the values into the original inequality. Two of the values will make the statement true. These two values identify the intervals which comprise the solution set of the inequality. The other two values make the statement false and identify the intervals that are to be excluded from the solution set. Because the inequality sign is strictly greater than, the interval end points must be excluded from your solution set.
John
My calculator said it, I believe it, that settles it
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