Question 211625
(x+6)(3x+12)(2x-6)>0
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Solve the EQUALITY to see values that are not part of the solution.
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x = -6 ; x = -4 ; x = 3
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Plot these value on a number line and check values in the intervals to
see where the solutions for the INEQUALITY are.
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Check x = -10 to get -*-*- > 0; false 
Check x = -5 to get +*-*- > 0 ; true so solutions in (-6,-4)
Check x = 0 to get +*+*- >0 ; false
Check x = 10 to get +*+*+ > 0 ; true so solutions in (3,+inf)
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Cheers,
Stan H.