| ( | 138 | + | x | ) | ÷ | 5 | × | 67 100 | = | x |
| 方程左边 = | ( | 138 | + | x | ) | × | 67 500 |
| ( | 138 | + | x | ) | × | 67 500 | = | x |
| 方程左边 = | 138 | × | 67 500 | + | x | × | 67 500 |
| = | 4623 250 | + | x | × | 67 500 |
4623 250 | + | 67 500 | x | = | x |
67 500 | x | − | x | = | - | 4623 250 |
| - | 433 500 | x | = | - | 4623 250 |
4623 250 | = | 433 500 | x |
433 500 | x | = | 4623 250 |
| x | = | 4623 250 | ÷ | 433 500 |
| = | 4623 250 | × | 500 433 |
| = | 4623 | × | 2 433 |
| x | = | 9246 433 |
| x | = | 21.353349 |