Question 250985: Use at least one inequality or compound inequality to express the answer. For answers with more than one inequality use a comma or the word 'or' to seperate the answers.
(x+5) (x-20) (x+3) > 0
Solution set is:
Thanks
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Use at least one inequality or compound inequality to express the answer. For answers with more than one inequality use a comma or the word 'or' to seperate the answers.
(x+5) (x-20) (x+3) > 0
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Find values of x which are not part of the solution:
x = -5, x= 20, x = -3
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Draw a number line and plot x = -5,-3,20
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Test a value in each of the four open intervals
in the inequality to see where the solutions lie.
Note: You need only check the sign of the product.
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If x = -7 you get: -*-*- < 0 so no solutions in (-inf,-5)
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If x = -4 you get: +*-*- > 0 so solutions in (-5,-3)
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If x = 19 you get: +*-*+ < 0 so no solutions in (-3,20)
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If x = 21, you get: +*+*+ > 0 so solutions in (20,+inf)
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Solution: (-5,-3)U(20,+inf)
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Cheers,
Stan H.
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