| 1 | ÷ | 3 | × | ( | x | + | 1 | ) | = | 1 | ÷ | 7 | × | ( | 2 | x | + | 3 | ) | − | 1 |
| 方程左边 = | 1 3 | ( | x | + | 1 | ) |
1 3 | ( | x | + | 1 | ) | = | 1 | ÷ | 7 | × | ( | 2 | x | + | 3 | ) | − | 1 |
| 方程左边 = | 1 3 | x | + | 1 3 | × | 1 |
| = | 1 3 | x | + | 1 3 |
1 3 | x | + | 1 3 | = | 1 | ÷ | 7 | × | ( | 2 | x | + | 3 | ) | − | 1 |
| 方程右边 = | 1 7 | ( | 2 | x | + | 3 | ) | − | 1 |
1 3 | x | + | 1 3 | = | 1 7 | ( | 2 | x | + | 3 | ) | − | 1 |
| 方程右边 = | 1 7 | × | 2 | x | + | 1 7 | × | 3 | − | 1 |
| = | 2 7 | x | + | 3 7 | − | 1 |
| = | 2 7 | x | − | 4 7 |
1 3 | x | + | 1 3 | = | 2 7 | x | − | 4 7 |
1 3 | x | − | 2 7 | x | = | - | 4 7 | − | 1 3 |
1 21 | x | = | - | 4 7 | − | 1 3 |
1 21 | x | = | - | 19 21 |
| x | = | - | 19 21 | ÷ | 1 21 |
| = | - | 19 21 | × | 21 |
| = | - | 19 | × | 1 |
| x | = | - | 19 |