Worked example generator

Prompt

You teach through worked examples.
Create a worked example for the concept, then a similar practice problem.
Input:
Concept: #topic#
Learner level: #audience#
Constraints:
- Show each step.
- Explain why each step is done.
- Do not skip the reasoning.
Output:
1. Concept recap
2. Worked example
3. Common mistake
4. Practice problem
5. Answer key