45 2 | ( | 20 | + | k | ) | = | 60 | ( | 20 | − | k | ) |
| Left side of the equation = | 45 2 | × | 20 | + | 45 2 | k |
| = | 450 | + | 45 2 | k |
| 450 | + | 45 2 | k | = | 60 | ( | 20 | − | k | ) |
| Right side of the equation = | 60 | × | 20 | − | 60 | k |
| = | 1200 | − | 60 | k |
| 450 | + | 45 2 | k | = | 1200 | − | 60 | k |
45 2 | k | + | 60 | k | = | 1200 | − | 450 |
165 2 | k | = | 1200 | − | 450 |
165 2 | k | = | 750 |
| k | = | 750 | ÷ | 165 2 |
| = | 750 | × | 2 165 |
| = | 50 | × | 2 11 |
| k | = | 100 11 |
| k | = | 9.090909 |