Absolute Values
Absolute Values Data Sufficiency problems test your ability to determine if given statements provide enough information about modulus equations or inequalities. You must assess sufficiency using the definition |x| = distance from zero, considering both positive and negative cases.
What You'll Learn
Introduction to Absolute Values
Absolute Values Data Sufficiency problems test your ability to determine if given statements provide enough information about modulus equations or inequalities. You must assess sufficiency using the definition |x| = distance from zero, considering both positive and negative cases.
Prerequisites
How to Solve Absolute Values Problems
Step 1: Identify what is being asked (value of x, range of x, etc.)
Step 2: Translate each statement into absolute value conditions
Step 3: Check if Statement (1) alone gives a unique answer
Step 4: Check if Statement (2) alone gives a unique answer
Step 5: Combine statements if needed
Step 6: Consider both positive and negative cases for absolute value equations
Step 7: Select the appropriate DS answer choice
Example Problem
Example: What is the value of x? Statement (1): |x| = 5 Statement (2): x² = 25 and x > 0 Solution: Step 1: Question asks for value of x Step 2: Statement (1): |x| = 5 → x = 5 or x = -5 → NOT sufficient alone (two values) Step 3: Statement (2): x² = 25 → x = 5 or x = -5, but x > 0 → x = 5 → SUFFICIENT alone Answer: Statement (2) alone is sufficient
Pro Tips & Tricks
- |x| = a (a>0) → x = a or x = -a (two solutions)
- |x| = 0 → x = 0 (one solution)
- |x| = a (a<0) → no solution
- |x| < a → -a < x < a
- |x| > a → x < -a or x > a
- |x - k| = a → x = k ± a (two solutions)
Shortcut Methods to Solve Faster
Common Mistakes to Avoid
Practice Worksheets
Practice makes perfect! Work through these worksheets to master Absolute Values. Each worksheet contains 20 questions with detailed explanations. Start from Worksheet 1 and progress through increasing difficulty levels.
Exam Importance
Absolute Values is an important topic for various competitive exams. Here's how frequently it appears:
Ready to Master Absolute Values?
Start with Worksheet 1 and work your way up to expert level! Each worksheet includes: