SOLUTION: Solve (x+15)(x-19)(x+13)>0

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Question 323502: Solve (x+15)(x-19)(x+13)>0
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Break up the number line into 4 regions.
Region 1:(-infinity,-15)
Region 2:(-15,-13)
Region 3:(-13,19)
Region 4:(19,infinity)
Choose an x value in each region (not an endpoint) and test the inequality.
If the x value solves the inequality, that region is part of the solution.
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Region 1: Let x=-20
+%28+x%2B15%29%28x-19%29%28x%2B13%29+%3E0
%28+-20%2B15%29%28-20-19%29%28-20%2B13%29%3E0
%28+-5%29%28-39%29%28-7%29%3E0
-1365%3E0
False, this region is not part of the solution.
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Region 2: Let x=-14
%28+x%2B15%29%28x-19%29%28x%2B13%29%3E0
%28+-14%2B15%29%28-14-19%29%28-14%2B13%29%3E0
%28+1%29%28-33%29%28-1%29%3E0
33%3E0
True, this region is part of the solution.
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Region 3: Let x=0
%28+x%2B15%29%28x-19%29%28x%2B13%29%3E0
%28+0%2B15%29%280-19%29%280%2B13%29%3E0
%28+15%29%28-19%29%2813%29%3E0
-3705%3E0
False, this region is not part of the solution.
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Region 4: Let x=20
%28+x%2B15%29%28x-19%29%28x%2B13%29%3E0
%28+20%2B15%29%2820-19%29%2820%2B13%29%3E0
%28+35%29%281%29%2833%29%3E0
1155%3E0
True, this region is part of the solution.
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Solution Region : (-15,-13) U (19,infinity)
(NOTE: Scale of y axis: 1 division=250 units)