Expanding Brackets − 1
multiply what is outside the bracket with each term inside the bracket
Example 1. Expand 4(a + 7)
Example 2. Expand 3a(1 + b + 5c)
Example 3. Expand s(t + 3u + 7)
| 4(a + 7) | = | 4 × (a + 7) | ||
| = | (4 × a) + (4 × 7) | |||
| = | 4a + 28 |
3a(1 + b + 5c)
| = | 3a × (1 + b + 5c) | |
| = | (3a × 1) + (3a × b) + (3a × 5c) | |
| = | 3a + 3ab + 15ac |
s(t + 3u + 7)
| = | s × (t + 3u + 7) | ||
| = | (s × t) + (s × 3u) + (s × 7) | ||
| = | st + 3su + 7s |
to: 
