| 16 | − | 4 | ( | 2 | k | + | 1 | ) | + | 4 | ( | k | − | 1 2 | ) | = | 0 |
| Left side of the equation = | 16 | − | 4 | × | 2 | k | − | 4 | × | 1 | + | 4 | ( | k | − | 1 2 | ) |
| = | 16 | − | 8 | k | − | 4 | + | 4 | ( | k | − | 1 2 | ) |
| = | 12 | − | 8 | k | + | 4 | ( | k | − | 1 2 | ) |
| = | 12 | − | 8 | k | + | 4 | k | − | 4 | × | 1 2 |
| = | 12 | − | 8 | k | + | 4 | k | − | 2 |
| = | 10 | − | 4 | k |
| 10 | − | 4 | k | = | 0 |
| - | 4 | k | = | 0 | − | 10 |
| - | 4 | k | = | - | 10 |
| 10 | = | 4 | k |
| 4 | k | = | 10 |
| k | = | 10 | ÷ | 4 |
| = | 10 | × | 1 4 |
| = | 5 | × | 1 2 |
| k | = | 5 2 |
| k | = | 2.5 |