Solve for x: x² - 7x - 18 = 0
Difficulty: Medium
About this MCQ
Medium GMAT item. Correct choice: D. x = 9 or x = -2.
- A. x = 10 or x = -3
Why not A: “x = 10 or x = -3” is not x = 9 or x = -2.
- B. x = 9 or x = -1
Why not B: “x = 9 or x = -1” is not x = 9 or x = -2.
- C. x = -9 or x = 2
Why not C: “x = -9 or x = 2” is not x = 9 or x = -2.
- D. x = 9 or x = -2 ✓
Correct answer
D. x = 9 or x = -2
Explanation
x = 9 or x = -2 (option D) is the accepted answer to “Solve for x: x² - 7x - 18 = 0”. Option A (x = 10 or x = -3) is a different value from x = 9 or x = -2. Option B (x = 9 or x = -1) is a different value from x = 9 or x = -2. Option C (x = -9 or x = 2) is a different value from x = 9 or x = -2. Keep x = 9 or x = -2 as the GMAT fact for this stem.
Source: Original practice question, MCQsHub
Tags: Math, Algebra, American Exams, GMAT
Submitted by: MCQsHub Editorial
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