| ( | X | − | 360 | ) | × | 75 100 | ÷ | 3800 | = | ( | X | − | 660 | ) | × | 75 100 | ÷ | 2800 |
| 方程左边 = | ( | X | − | 360 | ) | × | 3 15200 |
| ( | X | − | 360 | ) | × | 3 15200 | = | ( | X | − | 660 | ) | × | 75 100 | ÷ | 2800 |
| 方程左边 = | X | × | 3 15200 | − | 360 | × | 3 15200 |
| = | X | × | 3 15200 | − | 27 380 |
3 15200 | X | − | 27 380 | = | ( | X | − | 660 | ) | × | 75 100 | ÷ | 2800 |
| 方程右边 = | ( | X | − | 660 | ) | × | 3 11200 |
3 15200 | X | − | 27 380 | = | ( | X | − | 660 | ) | × | 3 11200 |
| 方程右边 = | X | × | 3 11200 | − | 660 | × | 3 11200 |
| = | X | × | 3 11200 | − | 99 560 |
3 15200 | X | − | 27 380 | = | 3 11200 | X | − | 99 560 |
3 15200 | X | − | 3 11200 | X | = | - | 99 560 | + | 27 380 |
| - | 3 42560 | X | = | - | 99 560 | + | 27 380 |
| - | 3 42560 | X | = | - | 225 2128 |
225 2128 | = | 3 42560 | X |
3 42560 | X | = | 225 2128 |
| X | = | 225 2128 | ÷ | 3 42560 |
| = | 225 2128 | × | 42560 3 |
| = | 75 | × | 20 |
| X | = | 1500 |