| ( | 3 | x | + | 1 | ) | ÷ | 4 | − | ( | x | − | 4 | ) | ÷ | 12 | = | ( | 1 | + | x | ) | ÷ | 3 |
| 方程左边 = | 3 | x | × | 1 4 | + | 1 | × | 1 4 | − | ( | x | − | 4 | ) | × | 1 12 |
| = | 3 4 | x | + | 1 4 | − | ( | x | − | 4 | ) | × | 1 12 |
| = | 3 4 | x | + | 1 4 | − | x | × | 1 12 | + | 4 | × | 1 12 |
| = | 3 4 | x | + | 1 4 | − | x | × | 1 12 | + | 1 3 |
| = | 2 3 | x | + | 7 12 |
2 3 | x | + | 7 12 | = | ( | 1 | + | x | ) | ÷ | 3 |
| 方程右边 = | 1 | × | 1 3 | + | x | × | 1 3 |
| = | 1 3 | + | x | × | 1 3 |
2 3 | x | + | 7 12 | = | 1 3 | + | 1 3 | x |
2 3 | x | − | 1 3 | x | = | 1 3 | − | 7 12 |
1 3 | x | = | 1 3 | − | 7 12 |
1 3 | x | = | - | 1 4 |
| x | = | - | 1 4 | ÷ | 1 3 |
| = | - | 1 4 | × | 3 |
| x | = | - | 3 4 |
| x | = | - 0.75 |