| 5500 | − | 5000 | − | 9 | ( | x | − | 210 | ) | − | 5 | ( | x | − | 200 | ) | = | 0 |
| 方程左边 = | 500 | − | 9 | ( | x | − | 210 | ) | − | 5 | ( | x | − | 200 | ) |
| 500 | − | 9 | ( | x | − | 210 | ) | − | 5 | ( | x | − | 200 | ) | = | 0 |
| 方程左边 = | 500 | − | 9 | x | + | 9 | × | 210 | − | 5 | ( | x | − | 200 | ) |
| = | 500 | − | 9 | x | + | 1890 | − | 5 | ( | x | − | 200 | ) |
| = | 2390 | − | 9 | x | − | 5 | ( | x | − | 200 | ) |
| = | 2390 | − | 9 | x | − | 5 | x | + | 5 | × | 200 |
| = | 2390 | − | 9 | x | − | 5 | x | + | 1000 |
| = | 3390 | − | 14 | x |
| 3390 | − | 14 | x | = | 0 |
| - | 14 | x | = | 0 | − | 3390 |
| - | 14 | x | = | - | 3390 |
| 3390 | = | 14 | x |
| 14 | x | = | 3390 |
| x | = | 3390 | ÷ | 14 |
| = | 3390 | × | 1 14 |
| = | 1695 | × | 1 7 |
| x | = | 1695 7 |
| x | = | 242.142857 |