Quadratic Expansion − Squaring Brackets
Squaring brackets means multiply the brackets by itself
Example 1. Expand (x + 4)2
Example 2. Expand (x − 4)2
| (x + 4)2 | = (x + 4)(x + 4) |
| = x2 + 4x + 4x + 16 | |
| = x2 + 8x + 16 |
| (x − 4)2 | = (x − 4)(x − 4) |
| = x2 − 4x − 4x + 16 | |
| = x2 − 8x + 16 |
to: 
