| ( | 1 | − | 4 | ÷ | 5 | ) | x | + | ( | 120 | − | x | − | 2 | ÷ | 7 | × | ( | 120 | − | x | ) | ) | = | 60 |
| 方程左边 = | 1 | x | − | 4 | ÷ | 5 | × | x | + | ( | 120 | − | x | − | 2 | ÷ | 7 | × | ( | 120 | − | x | ) | ) |
| = | 1 | x | − | 4 5 | x | + | ( | 120 | − | x | − | 2 | ÷ | 7 | × | ( | 120 | − | x | ) | ) |
| = | 1 5 | x | + | ( | 120 | − | x | − | 2 | ÷ | 7 | × | ( | 120 | − | x | ) | ) |
| = | 1 5 | x | + | 120 | − | x | − | 2 | ÷ | 7 | × | ( | 120 | − | x | ) |
| = | 1 5 | x | + | 120 | − | x | − | 2 7 | ( | 120 | − | x | ) |
| = | - | 4 5 | x | + | 120 | − | 2 7 | ( | 120 | − | x | ) |
| = | - | 4 5 | x | + | 120 | − | 2 7 | × | 120 | + | 2 7 | x |
| = | - | 4 5 | x | + | 120 | − | 240 7 | + | 2 7 | x |
| = | - | 18 35 | x | + | 600 7 |
| - | 18 35 | x | + | 600 7 | = | 60 |
| - | 18 35 | x | = | 60 | − | 600 7 |
| - | 18 35 | x | = | - | 180 7 |
180 7 | = | 18 35 | x |
18 35 | x | = | 180 7 |
| x | = | 180 7 | ÷ | 18 35 |
| = | 180 7 | × | 35 18 |
| = | 10 | × | 5 |
| x | = | 50 |