| ( | 50 | − | x | ÷ | 25 | ) | ( | 40000 | + | x | ) | = | 42025 |
| Left side of the equation = | 50 | ( | 40000 | + | x | ) | − | x | ÷ | 25 | × | ( | 40000 | + | x | ) |
| = | 50 | × | 40000 | + | 50 | x | − | x | × | 1 25 | ( | 40000 | + | x | ) |
| = | 2000000 | + | 50 | x | − | x | × | 1 25 | ( | 40000 | + | x | ) |
| = | 2000000 | + | 50 | x | − | x | × | 1 25 | × | 40000 | − | x | × | 1 25 | x |
| = | 2000000 | + | 50 | x | − | x | × | 1600 | − | x | × | 1 25 | x |
| = | 2000000 | − | 1550 | x | − | x | × | 1 25 | x |
| 2000000 | − | 1550 | x | − | x | × | 1 25 | x | = | 42025 |