Constructing Algebraic Expressions and Substitution: Exam Short-Note
1. Algebraic Expressions
- Letters (like x, y, n) are used to represent unknown numbers.
- Constructing: Translating word problems into math symbols.
Addition (+): 4 books plus n more books → 4 + n
Subtraction (-): a marbles, take away 5 → a - 5
2. Substitution
- Replacing an unknown letter with a specific number to find a final value.
Question: Find the value of x - 4 when x = 5
Step 1: Replace x with 5 → 5 - 4
Step 2: Solve → 1