SOLUTION: May I have some help with the following inequality? Solve the nonlinear inequality. Express the solution using interval notation. x^2 + x > 90

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Question 121667: May I have some help with the following inequality?
Solve the nonlinear inequality. Express the solution using interval notation.

x^2 + x > 90

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Solve the nonlinear inequality. Express the solution using interval notation.
x^2 + x > 90
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x^2+x-90 >0
Factor:
(x+10)(x-9)>0
Draw a number line; plot the points x=-10 and x=9 on it.
Test each of the three resulting intervals to see where the
solution set may be.
-------------
Test x=-11 in the inequality: (-11+10)(-11-9)>0; true
Test x = 0 in the inequality: (0+10)(0-9)>0 ; false
Test x = 10 in the inequality: (10+10)(10-9); true
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Two intervals comprise the solution set:
(-inf,-10) and (9,+inf)
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Cheers,
Stan H.