Question 519414: (x+20)(x-7)(x+4)>0
solution set?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! (x+20)(x-7)(x+4) > 0
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Draw a number line and plot x = -20, x = -4, and x = 7
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Test a value from each of the 4 intervals in the inequality:
(x+20)(x+4)(x-7) > 0
Test x = -30 ; -*-*- > 0 ; false
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Test x = -10 ; +*-*- > 0 ; true, so solutions in (-20,-4)
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Test x = 0 ; +*-*+ > 0 ; false
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Test 10 ; +*+*+ > 0 ; true, so solutions in (7,+oo)
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Solution: (-20,-4)U(7,+oo)
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Cheers,
Stan H.
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