| ( | 1000 | − | X | ) | × | 1 25 | + | X | × | 1 200 | = | ( | 1000 | − | X | ) | × | 7 250 |
| 方程左边 = | 1000 | × | 1 25 | − | X | × | 1 25 | + | 1 200 | X |
| = | 40 | − | X | × | 1 25 | + | 1 200 | X |
| = | 40 | − | 7 200 | X |
| 40 | − | 7 200 | X | = | ( | 1000 | − | X | ) | × | 7 250 |
| 方程右边 = | 1000 | × | 7 250 | − | X | × | 7 250 |
| = | 28 | − | X | × | 7 250 |
| 40 | − | 7 200 | X | = | 28 | − | 7 250 | X |
| - | 7 200 | X | + | 7 250 | X | = | 28 | − | 40 |
| - | 7 1000 | X | = | 28 | − | 40 |
| - | 7 1000 | X | = | - | 12 |
| 12 | = | 7 1000 | X |
7 1000 | X | = | 12 |
| X | = | 12 | ÷ | 7 1000 |
| = | 12 | × | 1000 7 |
| X | = | 12000 7 |
| X | = | 1714.285714 |