Question 202220: 2x^2+4x>15
Answer by RAY100(1637)   (Show Source):
You can put this solution on YOUR website! Just solve as equality then check inequalities
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2x^2 +4x >15
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2x^2 +4x-15=0
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using quadratic formula
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x=1.91,,,,x=-3.915
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on a number line this makes three areas
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x<-3.915,,,,test point (-4),,,checking inequality,,2(-4)^2 +4(-4) >15,,,32-16>15,,16>15,,,ok
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-3.91515,,,,not true
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x>1.91,,,,test point (+3),,,2(3)^2+4(3)>15,,18+12>15,,30>15 ,,,ok
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Therefore,,x>1.91,,,x<-3.915
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