| 10 | ( | 2 | x | + | 3 | ) | + | x | = | 10 | x | + | ( | 2 | x | + | 3 | ) | + | 5 |
| 方程左边 = | 10 | × | 2 | x | + | 10 | × | 3 | + | x |
| = | 20 | x | + | 30 | + | x |
| = | 21 | x | + | 30 |
| 21 | x | + | 30 | = | 10 | x | + | ( | 2 | x | + | 3 | ) | + | 5 |
| 方程右边 = | 10 | x | + | 2 | x | + | 3 | + | 5 |
| = | 12 | x | + | 8 |
| 21 | x | + | 30 | = | 12 | x | + | 8 |
| 21 | x | − | 12 | x | = | 8 | − | 30 |
| 9 | x | = | 8 | − | 30 |
| 9 | x | = | - | 22 |
| x | = | - | 22 | ÷ | 9 |
| = | - | 22 | × | 1 9 |
| x | = | - | 22 9 |
| x | = | - 2.444444 |