Topic explanation

Standard explanation

Distance form turns |x-a|<r into an inside interval and |x-a|>r into two outside intervals.

Key points

• absolute-value inequalities
• understand the idea
• apply it carefully
• keep the ideas separate
• Absolute-Value Inequalities: Distance form turns |x-a|<r into an inside interval and |x-a|>r into two outside intervals.
• WHAT — ABSOLUTE-VALUE INEQUALITIES: Distance form turns |x-a|<r into an inside interval and |x-a|>r into two outside intervals.
• HOW — Use the idea: Identify what is given, select this topic's rule or evidence, apply it one step at a time, and check
• CORE UNDERSTANDING: Distance form turns |x-a|<r into an inside interval and |x-a|>r into two outside intervals.

Labelled diagram