| ( | 5 | − | ( | 6 5 | x | ) | ) | ÷ | x | = | 25 | ÷ | ( | 3 | x | ) |
| 方程两边同时乘以: | x | , | ( | 3 | × | 1 | ) |
| ( | 5 | − | ( | 6 5 | x | ) | ) | ( | 3 | × | 1 | ) | = | 25 | × | 1 |
| 5 | ( | 3 | × | 1 | ) | − | ( | 6 5 | x | ) | ( | 3 | × | 1 | ) | = | 25 | × | 1 |
| 5 | ( | 3 | × | 1 | ) | − | ( | 6 5 | x | ) | ( | 3 | × | 1 | ) | = | 25 |
| 5 | × | 3 | × | 1 | − | ( | 6 5 | x | ) | ( | 3 | × | 1 | ) | = | 25 |
| 15 | − | ( | 6 5 | x | ) | ( | 3 | × | 1 | ) | = | 25 |
| 15 | − | 6 5 | x | ( | 3 | × | 1 | ) | = | 25 |
| 15 | − | 6 5 | x | × | 3 | × | 1 | = | 25 |
| 15 | − | 18 5 | x | = | 25 |
| - | 18 5 | x | = | 25 | − | 15 |
| - | 18 5 | x | = | 10 |
| - | 10 | = | 18 5 | x |
18 5 | x | = | - | 10 |
| x | = | - | 10 | ÷ | 18 5 |
| = | - | 10 | × | 5 18 |
| = | - | 5 | × | 5 9 |
| x | = | - | 25 9 |
| x | = | - 2.777778 |