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Solve the quadratic inequality. write the solution set in interval notation. x²−2x−48>0

a. x<−6 or x>8
b. x<−7 or x>9
c. x<−8 or x>6
d. x<−9 or x>7

User WesR
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1 Answer

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Final answer:

The solution to the quadratic inequality x²−2x−48>0 is found by factoring and testing intervals around the roots. In interval notation, the solution is (-∞, -6) ∪ (8, +∞), which corresponds to option (a): x < -6 or x > 8.

Step-by-step explanation:

To solve the quadratic inequality x²−2x−48>0, we first factor the quadratic expression. The expression can be factored into (x + 6)(x - 8) > 0. This means the product of (x + 6) and (x - 8) is greater than zero. To find the intervals where this inequality holds true, we consider the values x = -6 and x = 8, which are the roots of the quadratic equation.

We test intervals defined by these roots: (-∞, -6), (-6, 8), and (8, +∞). We find that the inequality is satisfied for x < -6 and x > 8. Therefore, in interval notation, the solution set is (-∞, -6) ∪ (8, +∞).

The correct answer matches option (a): x < -6 or x > 8.

User Richa
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