| 1300 | − | 6 | x | + | 10 | ( | 100 | − | x | ) | = | 378 |
| 方程左边 = | 1300 | − | 6 | x | + | 10 | × | 100 | − | 10 | x |
| = | 1300 | − | 6 | x | + | 1000 | − | 10 | x |
| = | 2300 | − | 16 | x |
| 2300 | − | 16 | x | = | 378 |
| - | 16 | x | = | 378 | − | 2300 |
| - | 16 | x | = | - | 1922 |
| 1922 | = | 16 | x |
| 16 | x | = | 1922 |
| x | = | 1922 | ÷ | 16 |
| = | 1922 | × | 1 16 |
| = | 961 | × | 1 8 |
| x | = | 961 8 |
| x | = | 120.125 |