| ( | a | − | 22 | ) | ( | - | 5 | a | + | 20 | ) | = | 325 |
| Left side of the equation = | a | ( | - | 5 | a | + | 20 | ) | − | 22 | ( | - | 5 | a | + | 20 | ) |
| = | - | a | × | 5 | a | + | a | × | 20 | − | 22 | ( | - | 5 | a | + | 20 | ) |
| = | - | a | × | 5 | a | + | 20 | a | + | 22 | × | 5 | a | − | 22 | × | 20 |
| = | - | a | × | 5 | a | + | 20 | a | + | 110 | a | − | 440 |
| = | - | a | × | 5 | a | + | 130 | a | − | 440 |
| - | a | × | 5 | a | + | 130 | a | − | 440 | = | 325 |