| 10 | x | + | ( | x | + | 3 | ) | = | 2 | ( | 10 | ( | x | + | 3 | ) | + | x | ) | − | 9 |
| 方程左边 = | 10 | x | + | x | + | 3 |
| = | 11 | x | + | 3 |
| 11 | x | + | 3 | = | 2 | ( | 10 | ( | x | + | 3 | ) | + | x | ) | − | 9 |
| 方程右边 = | 2 | × | 10 | ( | x | + | 3 | ) | + | 2 | x | − | 9 |
| = | 20 | ( | x | + | 3 | ) | + | 2 | x | − | 9 |
| = | 20 | x | + | 20 | × | 3 | + | 2 | x | − | 9 |
| = | 20 | x | + | 60 | + | 2 | x | − | 9 |
| = | 22 | x | + | 51 |
| 11 | x | + | 3 | = | 22 | x | + | 51 |
| 11 | x | − | 22 | x | = | 51 | − | 3 |
| - | 11 | x | = | 51 | − | 3 |
| - | 11 | x | = | 48 |
| - | 48 | = | 11 | x |
| 11 | x | = | - | 48 |
| x | = | - | 48 | ÷ | 11 |
| = | - | 48 | × | 1 11 |
| x | = | - | 48 11 |
| x | = | - 4.363636 |