| ( | x | − | 1 | ) | ( | x | − | 3 | ) | ( | x | − | 7 | ) | + | 2 | ( | x | − | 2 | ) | ( | x | − | 5 | ) | = | 0 |
| Left side of the equation = | x | ( | x | − | 3 | ) | ( | x | − | 7 | ) | − | 1 | ( | x | − | 3 | ) | ( | x | − | 7 | ) | + | 2 | ( | x | − | 2 | ) | ( | x | − | 5 | ) |
| = | x | x | ( | x | − | 7 | ) | − | x | × | 3 | ( | x | − | 7 | ) | − | 1 | ( | x | − | 3 | ) | ( | x | − | 7 | ) | + | 2 | ( | x | − | 2 | ) | ( | x | − | 5 | ) |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | ( | x | − | 7 | ) | − | 1 | ( | x | − | 3 | ) | ( | x | − | 7 | ) |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | x | × | 3 | × | 7 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | x | × | 21 | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 21 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 21 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 21 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 21 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 28 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 28 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 28 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 31 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 31 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 31 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 31 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 31 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 21 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 21 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 21 | x | − | 1 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 17 | x | − | 1 |
| x | x | x | − | x | x | × | 7 | − | x | × | 3 | x | + | 17 | x | − | 1 | = | 0 |