Topic explanation

Standard explanation

x²-9x-3 simplifies to x+3 for x!=3. At x=3 the original is undefined, even though 6 'looks like' the simplified value.

Key points

• hole at cancelled zero
• zeros of every original bottom
• cancelled still excluded
• keep the ideas separate
• From The Given Fraction: x²-9x-3 simplifies to x+3 for x!=3. At x=3 the original is undefined, even though 6 'looks lik
• WHAT — FROM THE GIVEN FRACTION: x²-9x-3 simplifies to x+3 for x!=3. At x=3 the original is undefined, even though 6 'looks lik
• 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: x²-9x-3 simplifies to x+3 for x!=3. At x=3 the original is undefined, even though 6 'looks lik

Labelled diagram