| X | ÷ | ( | 77 | ÷ | 18 5 | ) | − | X | ÷ | ( | 78 | ÷ | 18 5 | ) | = | 1 |
| 方程两边同时乘以: | ( | 77 | ÷ | 18 5 | ) |
| X | − | X | ÷ | ( | 78 | ÷ | 18 5 | ) | × | ( | 77 | ÷ | 18 5 | ) | = | 1 | ( | 77 | ÷ | 18 5 | ) |
| X | − | X | ÷ | ( | 78 | ÷ | 18 5 | ) | × | 77 | ÷ | 18 5 | = | 1 | ( | 77 | ÷ | 18 5 | ) |
| X | − | X | ÷ | ( | 78 | ÷ | 18 5 | ) | × | 77 | ÷ | 18 5 | = | 1 | × | 77 | ÷ | 18 5 |
| X | − | X | ÷ | ( | 78 | ÷ | 18 5 | ) | × | 385 18 | = | 385 18 |
| 方程两边同时乘以: | ( | 78 | ÷ | 18 5 | ) |
| X | ( | 78 | ÷ | 18 5 | ) | − | X | × | 385 18 | = | 385 18 | ( | 78 | ÷ | 18 5 | ) |
| X | × | 78 | ÷ | 18 5 | − | X | × | 385 18 | = | 385 18 | ( | 78 | ÷ | 18 5 | ) |
| X | × | 78 | ÷ | 18 5 | − | X | × | 385 18 | = | 385 18 | × | 78 | ÷ | 18 5 |
| X | × | 65 3 | − | X | × | 385 18 | = | 25025 54 |
5 18 | X | = | 25025 54 |
| X | = | 25025 54 | ÷ | 5 18 |
| = | 25025 54 | × | 18 5 |
| = | 5005 3 | × | 1 |
| X | = | 5005 3 |
| X | = | 1668.333333 |