Question 233497: please help me : this is the question
find the set of values of x which :
1) x^2-5x >0
2) 2x^2+3x
Please help im completely stuck
Thankyou
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! find the set of values of x which :
1) x^2-5x >0
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You do not directly solve inequlities.
You solve the boundary value which is the EQUALITY.
Solve x^2-5x = 0
x(x-5) = 0
x = 0 or x = 5
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Draw a number line and plot x=0 aand x = 5
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Now check a value from each of the resulting intervals
in x(x-5) >0 to see where the solutions of the INEQUALITY are.
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Checking x = -10 you get -*- > 0 ; true, so solutions in (-inf,0)
Checking x = 2 you get +*- >0 ; false, so no solutions in (0,5)
Checking x = 10 you get +*+ >0 ; true, so solutios in (5,+inf)
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Final answer: (-inf,0)U(5,+inf)
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2) 2x^2+3x
This is not an equation or an inequality so has no solution.
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Cheers,
Stan H.
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