| ( | 10 | − | 2 | x | ) | ( | 10 | − | 2 | x | ) | = | ( | 20 | ÷ | 3 | − | 4 | ÷ | 3 | × | x | ) | ( | 12 | − | 4 | ÷ | 3 | × | x | ) |
| 方程左边 = | 10 | ( | 10 | − | 2 | x | ) | − | 2 | x | ( | 10 | − | 2 | x | ) |
| = | 10 | × | 10 | − | 10 | × | 2 | x | − | 2 | x | ( | 10 | − | 2 | x | ) |
| = | 100 | − | 20 | x | − | 2 | x | ( | 10 | − | 2 | x | ) |
| = | 100 | − | 20 | x | − | 2 | x | × | 10 | + | 2 | x | × | 2 | x |
| = | 100 | − | 20 | x | − | 20 | x | + | 4 | x | x |
| = | 100 | − | 40 | x | + | 4 | x | x |
| 100 | − | 40 | x | + | 4 | x | x | = | ( | 20 | ÷ | 3 | − | 4 | ÷ | 3 | × | x | ) | ( | 12 | − | 4 | ÷ | 3 | × | x | ) |
| 方程右边 = | 20 | ÷ | 3 | × | ( | 12 | − | 4 | ÷ | 3 | × | x | ) | − | 4 | ÷ | 3 | × | x | ( | 12 | − | 4 | ÷ | 3 | × | x | ) |
| = | 20 3 | ( | 12 | − | 4 | ÷ | 3 | × | x | ) | − | 4 3 | x | ( | 12 | − | 4 | ÷ | 3 | × | x | ) |
| = | 20 3 | × | 12 | − | 20 3 | × | 4 | ÷ | 3 | × | x | − | 4 3 | x | ( | 12 | − | 4 | ÷ | 3 | × | x | ) |
| = | 80 | − | 80 9 | x | − | 4 3 | x | ( | 12 | − | 4 | ÷ | 3 | × | x | ) |
| = | 80 | − | 80 9 | x | − | 4 3 | x | × | 12 | + | 4 3 | x | × | 4 | ÷ | 3 | × | x |
| = | 80 | − | 80 9 | x | − | 16 | x | + | 16 9 | x | x |
| = | 80 | − | 224 9 | x | + | 16 9 | x | x |
| 100 | − | 40 | x | + | 4 | x | x | = | 80 | − | 224 9 | x | + | 16 9 | x | x |
| x1= | 9 5 |
| x2=5 |