| ( | 258 | × | 9 10 | − | x | ) | × | 77 100 | = | 258 | × | 1 2 |
| 方程左边 = | 258 | × | 9 10 | × | 77 100 | − | x | × | 77 100 |
| = | 89397 500 | − | x | × | 77 100 |
89397 500 | − | 77 100 | x | = | 258 | × | 1 2 |
| 方程右边 = | 129 |
89397 500 | − | 77 100 | x | = | 129 |
| - | 77 100 | x | = | 129 | − | 89397 500 |
| - | 77 100 | x | = | - | 24897 500 |
24897 500 | = | 77 100 | x |
77 100 | x | = | 24897 500 |
| x | = | 24897 500 | ÷ | 77 100 |
| = | 24897 500 | × | 100 77 |
| = | 24897 5 | × | 1 77 |
| x | = | 24897 385 |
| x | = | 64.667532 |