| ( | 25 | + | x | ) | ( | 500 | − | 10 | x | ) | = | 2700 |
| Left side of the equation = | 25 | ( | 500 | − | 10 | x | ) | + | x | ( | 500 | − | 10 | x | ) |
| = | 25 | × | 500 | − | 25 | × | 10 | x | + | x | ( | 500 | − | 10 | x | ) |
| = | 12500 | − | 250 | x | + | x | ( | 500 | − | 10 | x | ) |
| = | 12500 | − | 250 | x | + | x | × | 500 | − | x | × | 10 | x |
| = | 12500 | + | 250 | x | − | x | × | 10 | x |
| 12500 | + | 250 | x | − | x | × | 10 | x | = | 2700 |