| 4 | ( | 3 | × | 2 | − | 5 | k | ) | − | 2 | = | - | ( | 3 | − | 7 | k | ) |
| 方程左边 = | 4 | × | 3 | × | 2 | − | 4 | × | 5 | k | − | 2 |
| = | 24 | − | 20 | k | − | 2 |
| = | 22 | − | 20 | k |
| 22 | − | 20 | k | = | - | ( | 3 | − | 7 | k | ) |
| 方程右边 = | - | 3 | + | 7 | k |
| 22 | − | 20 | k | = | - | 3 | + | 7 | k |
| - | 20 | k | − | 7 | k | = | - | 3 | − | 22 |
| - | 27 | k | = | - | 3 | − | 22 |
| - | 27 | k | = | - | 25 |
| 25 | = | 27 | k |
| 27 | k | = | 25 |
| k | = | 25 | ÷ | 27 |
| = | 25 | × | 1 27 |
| k | = | 25 27 |
| k | = | 0.925926 |