| ( | 36 | × | 36 | − | 72 | x | + | x | x | ) | ( | x | x | − | 25 2 | × | 25 2 | ) | = | 100 | x | x |
| 方程左边 = | 36 | × | 36 | ( | x | x | − | 25 2 | × | 25 2 | ) | − | 72 | x | ( | x | x | − | 25 2 | × | 25 2 | ) | + | x | x | ( | x | x | − | 25 2 | × | 25 2 | ) |
| = | 1296 | ( | x | x | − | 25 2 | × | 25 2 | ) | − | 72 | x | ( | x | x | − | 25 2 | × | 25 2 | ) | + | x | x | ( | x | x | − | 25 2 | × | 25 2 | ) |
| = | 1296 | x | x | − | 1296 | × | 25 2 | × | 25 2 | − | 72 | x | ( | x | x | − | 25 2 | × | 25 2 | ) | + | x | x | ( | x | x | − | 25 2 | × | 25 2 | ) |
| = | 1296 | x | x | − | 202500 | − | 72 | x | ( | x | x | − | 25 2 | × | 25 2 | ) | + | x | x | ( | x | x | − | 25 2 | × | 25 2 | ) |
| = | 1296 | x | x | − | 202500 | − | 72 | x | x | x | + | 72 | x | × | 25 2 | × | 25 2 |
| = | 1296 | x | x | − | 202500 | − | 72 | x | x | x | + | 11250 | x | + | x | x |
| = | 1296 | x | x | − | 202500 | − | 72 | x | x | x | + | 11250 | x | + | x | x |
| = | 1296 | x | x | − | 202500 | − | 72 | x | x | x | + | 11250 | x | + | x | x |
| 1296 | x | x | − | 202500 | − | 72 | x | x | x | + | 11250 | x | + | x | x | = | 100 | x | x |