| ( | 3 4 | X | − | 1845 4 | − | 240 | ) | ÷ | 500 | = | ( | 3 4 | X | − | 1125 4 | − | 240 | ) | ÷ | 750 |
| 方程左边 = | 3 4 | X | × | 1 500 | − | 1845 4 | × | 1 500 | − | 240 | × | 1 500 |
| = | 3 2000 | X | − | 369 400 | − | 12 25 |
| = | 3 2000 | X | − | 561 400 |
3 2000 | X | − | 561 400 | = | ( | 3 4 | X | − | 1125 4 | − | 240 | ) | ÷ | 750 |
| 方程右边 = | 3 4 | X | × | 1 750 | − | 1125 4 | × | 1 750 | − | 240 | × | 1 750 |
| = | 1 1000 | X | − | 3 8 | − | 8 25 |
| = | 1 1000 | X | − | 139 200 |
3 2000 | X | − | 561 400 | = | 1 1000 | X | − | 139 200 |
3 2000 | X | − | 1 1000 | X | = | - | 139 200 | + | 561 400 |
1 2000 | X | = | - | 139 200 | + | 561 400 |
1 2000 | X | = | 283 400 |
| X | = | 283 400 | ÷ | 1 2000 |
| = | 283 400 | × | 2000 |
| = | 283 | × | 5 |
| X | = | 1415 |