| X | = | 3 20 | ( | 35 | − | X | ) | ( | 27 | − | X | ) |
| 方程右边 = | 3 20 | × | 35 | ( | 27 | − | X | ) | − | 3 20 | X | ( | 27 | − | X | ) |
| = | 21 4 | ( | 27 | − | X | ) | − | 3 20 | X | ( | 27 | − | X | ) |
| = | 21 4 | × | 27 | − | 21 4 | X | − | 3 20 | X | ( | 27 | − | X | ) |
| = | 567 4 | − | 21 4 | X | − | 3 20 | X | ( | 27 | − | X | ) |
| = | 567 4 | − | 21 4 | X | − | 3 20 | X | × | 27 | + | 3 20 | X | X |
| = | 567 4 | − | 21 4 | X | − | 81 20 | X | + | 3 20 | X | X |
| = | 567 4 | − | 93 10 | X | + | 3 20 | X | X |
| X | = | 567 4 | − | 93 10 | X | + | 3 20 | X | X |