Solve for x: x² + 9x + 18 = 0
Difficulty: Medium
About this MCQ
Medium ACT item. Correct choice: C. x = -6 or x = -3.
- A. x = 6 or x = 3
Why not A: “x = 6 or x = 3” is not x = -6 or x = -3.
- B. x = -6 or x = -2
Why not B: “x = -6 or x = -2” is not x = -6 or x = -3.
- C. x = -6 or x = -3 ✓
- D. x = -5 or x = -4
Why not D: “x = -5 or x = -4” is not x = -6 or x = -3.
Correct answer
C. x = -6 or x = -3
Explanation
x = -6 or x = -3 (option C) is the accepted answer to “Solve for x: x² + 9x + 18 = 0”. Option A (x = 6 or x = 3) is a different value from x = -6 or x = -3. Option B (x = -6 or x = -2) is a different value from x = -6 or x = -3. Option D (x = -5 or x = -4) is a different value from x = -6 or x = -3. Keep x = -6 or x = -3 as the ACT fact for this stem.
Source: Original practice question, MCQsHub
Tags: Math, Algebra, American Exams, ACT
Submitted by: MCQsHub Editorial