| ( | 13 | − | x | ) | ( | 13 | − | x | ) | × | 2 | = | ( | 17 | − | x | ) | ( | 17 | − | x | ) |
| Left side of the equation = | 13 | ( | 13 | − | x | ) | × | 2 | − | x | ( | 13 | − | x | ) | × | 2 |
| = | 26 | ( | 13 | − | x | ) | − | x | ( | 13 | − | x | ) | × | 2 |
| = | 26 | × | 13 | − | 26 | x | − | x | ( | 13 | − | x | ) | × | 2 |
| = | 338 | − | 26 | x | − | x | ( | 13 | − | x | ) | × | 2 |
| = | 338 | − | 26 | x | − | x | × | 13 | × | 2 | + | x | x | × | 2 |
| = | 338 | − | 26 | x | − | x | × | 26 | + | x | x | × | 2 |
| = | 338 | − | 52 | x | + | x | x | × | 2 |
| 338 | − | 52 | x | + | x | x | × | 2 | = | ( | 17 | − | x | ) | ( | 17 | − | x | ) |
| Right side of the equation = | 17 | ( | 17 | − | x | ) | − | x | ( | 17 | − | x | ) |
| = | 17 | × | 17 | − | 17 | x | − | x | ( | 17 | − | x | ) |
| = | 289 | − | 17 | x | − | x | ( | 17 | − | x | ) |
| = | 289 | − | 17 | x | − | x | × | 17 | + | x | x |
| = | 289 | − | 34 | x | + | x | x |
| 338 | − | 52 | x | + | x | x | × | 2 | = | 289 | − | 34 | x | + | x | x |