15 100 | = | ( | 1019 1000 | − | X | ) | ÷ | 1019 1000 |
| 方程右边 = | 1019 1000 | × | 1000 1019 | − | X | × | 1000 1019 |
| = | 1019 1019 | − | X | × | 1000 1019 |
15 100 | = | 1019 1019 | − | 1000 1019 | X |
1000 1019 | X | = | 1019 1019 | − | 15 100 |
1000 1019 | X | = | 17323 20380 |
| X | = | 17323 20380 | ÷ | 1000 1019 |
| = | 17323 20380 | × | 1019 1000 |
| X | = | 17652137 20380000 |
| X | = | 17323 20000 |
| X | = | 0.86615 |