3 4 | = | ( | x | − | 50 | ) | × | 1 20 | − | 15 | × | 1 20 |
| 方程右边 = | ( | x | − | 50 | ) | × | 1 20 | − | 3 4 |
3 4 | = | ( | x | − | 50 | ) | × | 1 20 | − | 3 4 |
| 方程右边 = | x | × | 1 20 | − | 50 | × | 1 20 | − | 3 4 |
| = | x | × | 1 20 | − | 5 2 | − | 3 4 |
| = | 1 20 | x | − | 13 4 |
3 4 | = | 1 20 | x | − | 13 4 |
| - | 1 20 | x | = | - | 13 4 | − | 3 4 |
| - | 1 20 | x | = | - | 4 |
| 4 | = | 1 20 | x |
1 20 | x | = | 4 |
| x | = | 4 | ÷ | 1 20 |
| = | 4 | × | 20 |
| x | = | 80 |