| 60 | ( | 2 | x | + | x | + | 2 | ) | = | 55 | ( | 2 | x | + | 2 | ) | + | 60 | x |
| 方程左边 = | 60 | × | 2 | x | + | 60 | x | + | 60 | × | 2 |
| = | 120 | x | + | 60 | x | + | 120 |
| = | 180 | x | + | 120 |
| 180 | x | + | 120 | = | 55 | ( | 2 | x | + | 2 | ) | + | 60 | x |
| 方程右边 = | 55 | × | 2 | x | + | 55 | × | 2 | + | 60 | x |
| = | 110 | x | + | 110 | + | 60 | x |
| = | 170 | x | + | 110 |
| 180 | x | + | 120 | = | 170 | x | + | 110 |
| 180 | x | − | 170 | x | = | 110 | − | 120 |
| 10 | x | = | 110 | − | 120 |
| 10 | x | = | - | 10 |
| x | = | - | 10 | ÷ | 10 |
| = | - | 10 | × | 1 10 |
| = | - | 1 | × | 1 |
| x | = | - | 1 |