Question 879299: Solve the inequality (x + 3)(5 - x) < 0. Give your solution in interval notation
Found 2 solutions by solver91311, josgarithmetic:
Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website!
Write the inequality as an equation. Such equation will have two zeros which divides the  -axis into three intervals, negative infinity to the lesser of the two zeros, the interval between the two zeroes, and the larger of the two zeroes to infinity.
Select a value from each of the three intervals and evaluate the equation at each value. Any value that produces a negative result indicates an interval that satisfies the original inequality.
John
My calculator said it, I believe it, that settles it
Answer by josgarithmetic(39617)  (Show Source):
You can put this solution on YOUR website! Two obvious critical values for x are -3 and 5. Check a value in each interval.
(-oo, -3), pick -4=x.
(-)(+)=(-)<0 TRUE.
(-3, 5), pick x=0.
(+)(+)=(+)<0, basically FALSE.
(5, oo), pick 10=x.
(+)(-)=(-)<0 TRUE.
Statement is true for x in (-oo, -3) OR (5, oo).
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