Question

Solve the inequality: (x − 1)/(x + 2) > 2. Which of the following represents the solution set? (

  • A x < −5 (
  • B −5 < x < −2 (
  • C −2 < x < 1 (
  • D x > 1
A A Correct Answer Incorrect Answer
B B Correct Answer Incorrect Answer
C C Correct Answer Incorrect Answer
D D Correct Answer Incorrect Answer

Solution

ATQ, x ≠ −2. (x − 1)/(x + 2) > 2 ⇒ (x − 1)/(x + 2) − 2 > 0 ⇒ (x − 1 − 2x − 4)/(x + 2) > 0 ⇒ (−x − 5)/(x + 2) > 0 Multiply numerator and denominator by −1 (reverses inequality): (x + 5)/(x + 2) < 0. Critical points: x = −5, x = −2. Sign analysis: For x < −5: numerator < 0, denominator < 0 ⇒ ratio > 0 (reject). For −5 < x < −2: numerator > 0, denominator < 0 ⇒ ratio < 0 (accept). For x > −2: numerator > 0, denominator > 0 ⇒ ratio > 0 (reject). Solution: −5 < x < −2.

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