| 500 | ( | a | − | 35 | ) | + | ( | 58 | − | a | ) | a | ( | a | − | 35 | ) | = | 8400 |
| Left side of the equation = | 500 | a | − | 500 | × | 35 | + | ( | 58 | − | a | ) | a | ( | a | − | 35 | ) |
| = | 500 | a | − | 17500 | + | ( | 58 | − | a | ) | a | ( | a | − | 35 | ) |
| = | 500 | a | − | 17500 | + | 58 | a | ( | a | − | 35 | ) | − | a | a | ( | a | − | 35 | ) |
| = | 500 | a | − | 17500 | + | 58 | a | a | − | 58 | a | × | 35 | − | a | a | ( | a | − | 35 | ) |
| = | 500 | a | − | 17500 | + | 58 | a | a | − | 2030 | a | − | a | a | ( | a | − | 35 | ) |
| = | - | 1530 | a | − | 17500 | + | 58 | a | a | − | a | a | ( | a | − | 35 | ) |
| = | - | 1530 | a | − | 17500 | + | 58 | a | a | − | a | a | a | + | a | a | × | 35 |
| - | 1530 | a | − | 17500 | + | 58 | a | a | − | a | a | a | + | a | a | × | 35 | = | 8400 |