| X | × | 30 | × | 12 | + | X | × | 30 100 | × | 60 | × | 12 | = | X | × | 60 | × | 4 | + | X | × | 20 | × | 12 | + | 24000 |
| 方程左边 = | X | × | 360 | + | X | × | 216 |
| = | 576 | X |
| 576 | X | = | X | × | 60 | × | 4 | + | X | × | 20 | × | 12 | + | 24000 |
| 方程右边 = | X | × | 240 | + | X | × | 240 | + | 24000 |
| = | 480 | X | + | 24000 |
| 576 | X | = | 480 | X | + | 24000 |
| 576 | X | − | 480 | X | = | 24000 |
| 96 | X | = | 24000 |
| X | = | 24000 | ÷ | 96 |
| = | 24000 | × | 1 96 |
| = | 250 | × | 1 |
| X | = | 250 |