| X | − | 900 | − | ( | 13 100 | X | − | 50 | X | ÷ | 10000 | ) | × | 1 10 | = | 0 |
| 方程左边 = | X | − | 900 | − | 13 100 | X | × | 1 10 | + | 50 | X | ÷ | 10000 | × | 1 10 |
| = | X | − | 900 | − | 13 1000 | X | + | 1 2000 | X |
| = | 79 80 | X | − | 900 |
79 80 | X | − | 900 | = | 0 |
79 80 | X | = | 0 | + | 900 |
79 80 | X | = | 900 |
| X | = | 900 | ÷ | 79 80 |
| = | 900 | × | 80 79 |
| X | = | 72000 79 |
| X | = | 911.392405 |