| ( | 100 | k | + | 40 | ) | − | ( | 150 | ( | 10000 | − | k | ) | + | 25 | ) | = | 0 |
| Left side of the equation = | 100 | k | + | 40 | − | ( | 150 | ( | 10000 | − | k | ) | + | 25 | ) |
| = | 100 | k | + | 40 | − | 150 | ( | 10000 | − | k | ) | − | 25 |
| = | 100 | k | + | 15 | − | 150 | ( | 10000 | − | k | ) |
| = | 100 | k | + | 15 | − | 150 | × | 10000 | + | 150 | k |
| = | 100 | k | + | 15 | − | 1500000 | + | 150 | k |
| = | 250 | k | − | 1499985 |
| 250 | k | − | 1499985 | = | 0 |
| 250 | k | = | 0 | + | 1499985 |
| 250 | k | = | 1499985 |
| k | = | 1499985 | ÷ | 250 |
| = | 1499985 | × | 1 250 |
| = | 299997 | × | 1 50 |
| k | = | 299997 50 |
| k | = | 5999.94 |