| 5 | ( | x | − | 30 | ) | = | ( | 150 | − | x | ) | ÷ | 12 |
| 方程左边 = | 5 | x | − | 5 | × | 30 |
| = | 5 | x | − | 150 |
| 5 | x | − | 150 | = | ( | 150 | − | x | ) | ÷ | 12 |
| 方程右边 = | 150 | × | 1 12 | − | x | × | 1 12 |
| = | 25 2 | − | x | × | 1 12 |
| 5 | x | − | 150 | = | 25 2 | − | 1 12 | x |
| 5 | x | + | 1 12 | x | = | 25 2 | + | 150 |
61 12 | x | = | 25 2 | + | 150 |
61 12 | x | = | 325 2 |
| x | = | 325 2 | ÷ | 61 12 |
| = | 325 2 | × | 12 61 |
| = | 325 | × | 6 61 |
| x | = | 1950 61 |
| x | = | 31.967213 |