| 77 | + | a | ÷ | 123 | − | a | = | 2 | ÷ | 3 |
| 方程左边 = | 77 | − | 122 123 | a |
| 77 | − | 122 123 | a | = | 2 | ÷ | 3 |
| 方程右边 = | 2 3 |
| 77 | − | 122 123 | a | = | 2 3 |
| - | 122 123 | a | = | 2 3 | − | 77 |
| - | 122 123 | a | = | - | 229 3 |
229 3 | = | 122 123 | a |
122 123 | a | = | 229 3 |
| a | = | 229 3 | ÷ | 122 123 |
| = | 229 3 | × | 123 122 |
| = | 229 | × | 41 122 |
| a | = | 9389 122 |
| a | = | 76.959016 |