139 5 | n | − | ( | n | + | 1 | ) | n | ÷ | 2 | × | 24 25 | = | 1509 5 |
| 方程左边 = | 139 5 | n | − | ( | n | + | 1 | ) | n | × | 12 25 |
139 5 | n | − | ( | n | + | 1 | ) | n | × | 12 25 | = | 1509 5 |
| 方程左边 = | 139 5 | n | − | n | n | × | 12 25 | − | 1 | n | × | 12 25 |
| = | 139 5 | n | − | n | n | × | 12 25 | − | 12 25 | n |
| = | 683 25 | n | − | n | n | × | 12 25 |
683 25 | n | − | n | n | × | 12 25 | = | 1509 5 |
| n2= | 503 12 |