SOLUTION: Hello. I was hoping someone could please help me with a question that I do not know how to solve. My question has two parts and is as follows: Find and graph the solution set:

Algebra ->  Graphs -> SOLUTION: Hello. I was hoping someone could please help me with a question that I do not know how to solve. My question has two parts and is as follows: Find and graph the solution set:       Log On


   



Question 327286: Hello. I was hoping someone could please help me with a question that I do not know how to solve.
My question has two parts and is as follows:
Find and graph the solution set:
A. x^3 - 16x > 0
B. x^2 - 5x <= -6
I don't know how to solve these questions because they are raised to different powers, so I don't know how to solve for x.
Also, could you please explain to me how I'd go about graphing these inequalities?
Thank you so much.

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Solved earlier today
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x%5E3-16x%3E0
x%28x%5E2-16%29%3E0
x%28x-4%29%28x%2B4%29%3E0
Break up the number line into 4 regions:
Region 1 : (-infinity,-4)
Region 2 : (-4,0)
Region 3 : (0,4)
Region 4 : (4,infinity)
Choose a point in the region (not an endpoint).
Test the inequality.
If the inequality is satisfied, the region is part of the solution.
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Region 1:x=-5
x%28x-4%29%28x%2B4%29%3E0
-5%28-5-4%29%28-5%2B4%29%3E0
-45%3E0
False, this region is not part of the solution.
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Region 2:x=-2
x%28x-4%29%28x%2B4%29%3E0
-2%28-6%29%282%29%3E0
24%3E0
True, this region is part of the solution.
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Region 3:x=2
x%28x-4%29%28x%2B4%29%3E0
2%28-2%29%286%29%3E0
-24%3E0
False, this region is not part of the solution.
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Region 4:x=5
x%28x-4%29%28x%2B4%29%3E0
5%281%29%289%29%3E0
45%3E0
True, this region is part of the solution.
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The solution region is (-4,0) U (4,infinity).
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Verified graphically
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+graph%28+300%2C+300%2C+-10%2C+10%2C+-50%2C+50%2C+x%2A%28x-4%29%2A%28x%2B4%29%29%29+
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Similarly,
x%5E2-5x%3C=-6
x%5E2-5x%2B6%3C=0
%28x-2%29%28x-3%29%3C=0
Break up the number line into 3 regions:
Region 1 : (-infinity,2)
Region 2 : (2,3)
Region 3 : (3,infinity)
Choose a point in the region (not an endpoint).
Test the inequality.
If the inequality is satisfied, the region is part of the solution.
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Region 1:x=0
%28x-2%29%28x-3%29%3C=0
%28-2%29%28-3%29%3C=0
6%3E0
True, this region is part of the solution.
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Region 1:x=0
%28x-2%29%28x-3%29%3C=0
%28-2%29%28-3%29%3C=0
6%3C=0
False, this region is not part of the solution.
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Region 2:x=2.5
%28x-2%29%28x-3%29%3C=0
%280.5%29%28-0.5%29%3C=0
-0.25%3C=0
True, this region is part of the solution.
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Region 3:x=4
%28x-2%29%28x-3%29%3C=0
%282%29%281%29%3C=0
2%3C=0
False, this region is not part of the solution.
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The solution region is [2,3].
Since the inequality includes the "=" the brackets denote that 2 and 3 are included as part of the solution.
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graph%28300%2C300%2C-2%2C6%2C-1%2C1%2C%28x-2%29%2A%28x-3%29%29