| ( | 55 | − | a | ) | ( | a | − | 35 | ) | ÷ | 10 | = | 1760 |
| 方程左边 = | 55 | ( | a | − | 35 | ) | × | 1 10 | − | a | ( | a | − | 35 | ) | × | 1 10 |
| = | 11 2 | ( | a | − | 35 | ) | − | a | ( | a | − | 35 | ) | × | 1 10 |
| = | 11 2 | a | − | 11 2 | × | 35 | − | a | ( | a | − | 35 | ) | × | 1 10 |
| = | 11 2 | a | − | 385 2 | − | a | ( | a | − | 35 | ) | × | 1 10 |
| = | 11 2 | a | − | 385 2 | − | a | a | × | 1 10 | + | a | × | 35 | × | 1 10 |
| = | 11 2 | a | − | 385 2 | − | a | a | × | 1 10 | + | a | × | 7 2 |
| = | 9 | a | − | 385 2 | − | a | a | × | 1 10 |
| 9 | a | − | 385 2 | − | a | a | × | 1 10 | = | 1760 |