| ( | 10 | + | a | ÷ | 25 | ) | ( | 500 | − | a | ) | = | 5400 |
| Left side of the equation = | 10 | ( | 500 | − | a | ) | + | a | ÷ | 25 | × | ( | 500 | − | a | ) |
| = | 10 | × | 500 | − | 10 | a | + | a | × | 1 25 | ( | 500 | − | a | ) |
| = | 5000 | − | 10 | a | + | a | × | 1 25 | ( | 500 | − | a | ) |
| = | 5000 | − | 10 | a | + | a | × | 1 25 | × | 500 | − | a | × | 1 25 | a |
| = | 5000 | − | 10 | a | + | a | × | 20 | − | a | × | 1 25 | a |
| = | 5000 | + | 10 | a | − | a | × | 1 25 | a |
| 5000 | + | 10 | a | − | a | × | 1 25 | a | = | 5400 |