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