| - | 5 | ÷ | 2 | × | ( | 4 | − | 6 | k | ) | = | - | 1 | ÷ | 3 | × | ( | 12 | k | + | 3 | + | 3 | k | ) |
| 方程左边 = | - | 5 2 | ( | 4 | − | 6 | k | ) |
| - | 5 2 | ( | 4 | − | 6 | k | ) | = | - | 1 | ÷ | 3 | × | ( | 12 | k | + | 3 | + | 3 | k | ) |
| 方程左边 = | - | 5 2 | × | 4 | + | 5 2 | × | 6 | k |
| = | - | 10 | + | 15 | k |
| - | 10 | + | 15 | k | = | - | 1 | ÷ | 3 | × | ( | 12 | k | + | 3 | + | 3 | k | ) |
| 方程右边 = | - | 1 3 | ( | 12 | k | + | 3 | + | 3 | k | ) |
| - | 10 | + | 15 | k | = | - | 1 3 | ( | 12 | k | + | 3 | + | 3 | k | ) |
| 方程右边 = | - | 1 3 | × | 12 | k | − | 1 3 | × | 3 | − | 1 3 | × | 3 | k |
| = | - | 4 | k | − | 1 | − | 1 | k |
| = | - | 5 | k | − | 1 |
| - | 10 | + | 15 | k | = | - | 5 | k | − | 1 |
| 15 | k | + | 5 | k | = | - | 1 | + | 10 |
| 20 | k | = | - | 1 | + | 10 |
| 20 | k | = | 9 |
| k | = | 9 | ÷ | 20 |
| = | 9 | × | 1 20 |
| k | = | 9 20 |
| k | = | 0.45 |