| ( | x | − | 4 | ) | ( | x | − | 1 | ) | ( | x | − | 9 | ) | + | 2 | + | 2 | − | 4 | ( | x | − | 1 | ) | − | x | + | 4 | − | x | + | 9 | = | 0 |
| 方程左边 = | ( | x | − | 4 | ) | ( | x | − | 1 | ) | ( | x | − | 9 | ) | + | 17 | − | 4 | ( | x | − | 1 | ) | − | 2 | x |
| ( | x | − | 4 | ) | ( | x | − | 1 | ) | ( | x | − | 9 | ) | + | 17 | − | 4 | ( | x | − | 1 | ) | − | 2 | x | = | 0 |
| 方程左边 = | x | ( | x | − | 1 | ) | ( | x | − | 9 | ) | − | 4 | ( | x | − | 1 | ) | ( | x | − | 9 | ) | + | 17 | − | 4 | ( | x | − | 1 | ) | − | 2 | x |
| = | x | x | ( | x | − | 9 | ) | − | x | × | 1 | ( | x | − | 9 | ) | − | 4 | ( | x | − | 1 | ) | ( | x | − | 9 | ) | + | 17 | − | 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 | + | 7 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 7 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 7 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 7 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 7 | 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 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 43 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 47 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 47 | x | − | 4 |
| = | x | x | x | − | x | x | × | 9 | − | x | × | 1 | x | + | 47 | 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 |