| b. Original equation. |  |
| Multiply both sides by 3. | 12 + 3.12x = –300 |
| Subtract 12 from both sides. | –12 + 12 + 3.12x = –300 – 12 |
| 3.12x = –312 | |
| Divide both sides by 3.12. | x = –100 |
| b. Original equation. | |
| Multiply both sides by 3. | 12 + 3.12x = –300 |
| Subtract 12 from both sides. | –12 + 12 + 3.12x = –300 – 12 |
| 3.12x = –312 | |
| Divide both sides by 3.12. | x = –100 |