| ( | x | − | 12 5 | ) | ÷ | 20 | + | 2 5 | = | ( | x | + | 8 5 | ) | ÷ | 18 |
| 方程左边 = | x | × | 1 20 | − | 12 5 | × | 1 20 | + | 2 5 |
| = | x | × | 1 20 | − | 3 25 | + | 2 5 |
| = | 1 20 | x | + | 7 25 |
1 20 | x | + | 7 25 | = | ( | x | + | 8 5 | ) | ÷ | 18 |
| 方程右边 = | x | × | 1 18 | + | 8 5 | × | 1 18 |
| = | x | × | 1 18 | + | 4 45 |
1 20 | x | + | 7 25 | = | 1 18 | x | + | 4 45 |
1 20 | x | − | 1 18 | x | = | 4 45 | − | 7 25 |
| - | 1 180 | x | = | 4 45 | − | 7 25 |
| - | 1 180 | x | = | - | 43 225 |
43 225 | = | 1 180 | x |
1 180 | x | = | 43 225 |
| x | = | 43 225 | ÷ | 1 180 |
| = | 43 225 | × | 180 |
| = | 43 5 | × | 4 |
| x | = | 172 5 |
| x | = | 34.4 |