| - | ( | - | 71 | ÷ | ( | - | 8 | x | + | 15 | ) | + | 4 | ) | + | 4 | = | 1 |
| 71 | ÷ | ( | - | 8 | x | + | 15 | ) | − | 4 | + | 4 | = | 1 |
| 71 | ÷ | ( | - | 8 | x | + | 15 | ) | − | 0 | = | 1 |
| 方程两边同时乘以: | ( | - | 8 | x | + | 15 | ) |
| 71 | − | 0 | = | 1 | ( | - | 8 | x | + | 15 | ) |
| 71 | − | 0 | = | - | 1 | × | 8 | x | + | 1 | × | 15 |
| 71 | − | 0 | = | - | 8 | x | + | 15 |
| 71 | = | - | 8 | x | + | 15 |
| 8 | x | = | 15 | − | 71 |
| 8 | x | = | - | 56 |
| x | = | - | 56 | ÷ | 8 |
| = | - | 56 | × | 1 8 |
| = | - | 7 | × | 1 |
| x | = | - | 7 |