| 7 | ÷ | 102 | + | 8 | ÷ | 447 10 | + | X | ÷ | 255 2 | + | ( | 412 5 | − | X | ) | ÷ | 1000 | = | 921 2000 |
| 方程左边 = | 7 102 | + | 80 447 | + | X | × | 2 255 | + | ( | 412 5 | − | X | ) | × | 1 1000 |
| = | 3763 15198 | + | 2 255 | X | + | ( | 412 5 | − | X | ) | × | 1 1000 |
3763 15198 | + | 2 255 | X | + | ( | 412 5 | − | X | ) | × | 1 1000 | = | 921 2000 |
| 方程左边 = | 3763 15198 | + | 2 255 | X | + | 412 5 | × | 1 1000 | − | X | × | 1 1000 |
| = | 3763 15198 | + | 2 255 | X | + | 103 1250 | − | X | × | 1 1000 |
| = | 1567286 4749375 | + | 349 51000 | X |
1567286 4749375 | + | 349 51000 | X | = | 921 2000 |
349 51000 | X | = | 921 2000 | − | 1567286 4749375 |
349 51000 | X | = | 9916819 75990000 |
| X | = | 9916819 75990000 | ÷ | 349 51000 |
| = | 9916819 75990000 | × | 51000 349 |
| = | 9916819 1490 | × | 1 349 |
| X | = | 9916819 520010 |
| X | = | 19.070439 |