1. Definition
Multiplying a sum by a number gives the same as multiplying each addend and adding the products.
2. Formula & Notation
| a | Outside factor |
| b, c | Addends inside |
3. Properties & Laws
- a(b+c)=ab+ac;
- For subtraction a(b−c)=ab−ac;
- Reversible (factoring);
- Works for integers, decimals, fractions.
4. Steps
- Enter a, b, c;
- Click "Calculate";
- Or click "Load Example".
5. Worked Examples
Example: 3(4+5).
Solution: left 27; right 12+15=27.
6. Common Pitfalls
a multiplies both b and c;
Do not skip a term;
Associative is multiplication only.