| x | = | 61 20 | ( | 1 | − | x | ) | ( | 1 10 | − | x | ) |
| 方程右边 = | 61 20 | × | 1 | ( | 1 10 | − | x | ) | − | 61 20 | x | ( | 1 10 | − | x | ) |
| = | 61 20 | ( | 1 10 | − | x | ) | − | 61 20 | x | ( | 1 10 | − | x | ) |
| = | 61 20 | × | 1 10 | − | 61 20 | x | − | 61 20 | x | ( | 1 10 | − | x | ) |
| = | 61 200 | − | 61 20 | x | − | 61 20 | x | ( | 1 10 | − | x | ) |
| = | 61 200 | − | 61 20 | x | − | 61 20 | x | × | 1 10 | + | 61 20 | x | x |
| = | 61 200 | − | 61 20 | x | − | 61 200 | x | + | 61 20 | x | x |
| = | 61 200 | − | 671 200 | x | + | 61 20 | x | x |
| x | = | 61 200 | − | 671 200 | x | + | 61 20 | x | x |