| ( | 3 4 | X | − | 270 | ) | ÷ | 3600 | = | ( | 3 4 | X | − | 270 | − | 144 | ) | ÷ | 3000 |
| 方程左边 = | 3 4 | X | × | 1 3600 | − | 270 | × | 1 3600 |
| = | 1 4800 | X | − | 3 40 |
1 4800 | X | − | 3 40 | = | ( | 3 4 | X | − | 270 | − | 144 | ) | ÷ | 3000 |
| 方程右边 = | 3 4 | X | × | 1 3000 | − | 270 | × | 1 3000 | − | 144 | × | 1 3000 |
| = | 1 4000 | X | − | 9 100 | − | 6 125 |
| = | 1 4000 | X | − | 69 500 |
1 4800 | X | − | 3 40 | = | 1 4000 | X | − | 69 500 |
1 4800 | X | − | 1 4000 | X | = | - | 69 500 | + | 3 40 |
| - | 1 24000 | X | = | - | 69 500 | + | 3 40 |
| - | 1 24000 | X | = | - | 63 1000 |
63 1000 | = | 1 24000 | X |
1 24000 | X | = | 63 1000 |
| X | = | 63 1000 | ÷ | 1 24000 |
| = | 63 1000 | × | 24000 |
| = | 63 | × | 24 |
| X | = | 1512 |