| x | ( | x | + | 10 | ) | ( | x | − | 10 | ) | = | 24000 |
| Left side of the equation = | x | x | ( | x | − | 10 | ) | + | x | × | 10 | ( | x | − | 10 | ) |
| = | x | x | x | − | x | x | × | 10 | + | x | × | 10 | ( | x | − | 10 | ) |
| = | x | x | x | − | x | x | × | 10 | + | x | × | 10 | x | − | x | × | 10 | × | 10 |
| = | x | x | x | − | x | x | × | 10 | + | x | × | 10 | x | − | x | × | 100 |
| x | x | x | − | x | x | × | 10 | + | x | × | 10 | x | − | 100 | x | = | 24000 |