| ( | x | − | 4 | ) | ( | x | − | 1 | ) | ( | x | − | 9 | ) | − | 4 | − | 4 | ( | x | − | 1 | ) | − | ( | x | − | 9 | ) | − | ( | x | − | 4 | ) | = | 0 |
| Left side of the equation = | x | ( | x | − | 1 | ) | ( | x | − | 9 | ) | − | 4 | ( | x | − | 1 | ) | ( | x | − | 9 | ) | − | 4 | − | 4 | ( | x | − | 1 | ) | − | ( | x | − | 9 | ) | − | ( | x | − | 4 | ) |
| = | x | x | ( | x | − | 9 | ) | − | x | × | 1 | ( | x | − | 9 | ) | − | 4 | ( | x | − | 1 | ) | ( | x | − | 9 | ) | − | 4 | − | 4 | ( | x | − | 1 | ) |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | ( | x | − | 9 | ) | − | 4 | ( | x | − | 1 | ) | ( | x | − | 9 | ) |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | x | × | 1 | × | 9 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | x | × | 9 | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 9 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 9 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 9 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 9 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 45 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 45 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 45 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 49 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 49 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 49 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 45 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 45 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 44 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 44 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 43 | x | − | 4 |
| x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 43 | x | − | 4 | = | 0 |