1 20 | X | + | X | × | 2 | = | 63 100 | ( | 7 20 | − | X | ) |
| 方程左边 = | 41 20 | X |
41 20 | X | = | 63 100 | ( | 7 20 | − | X | ) |
| 方程右边 = | 63 100 | × | 7 20 | − | 63 100 | X |
| = | 441 2000 | − | 63 100 | X |
41 20 | X | = | 441 2000 | − | 63 100 | X |
41 20 | X | + | 63 100 | X | = | 441 2000 |
67 25 | X | = | 441 2000 |
| X | = | 441 2000 | ÷ | 67 25 |
| = | 441 2000 | × | 25 67 |
| = | 441 80 | × | 1 67 |
| X | = | 441 5360 |
| X | = | 0.082276 |