| ( | 35 | + | a | ) | ( | 1155 | − | 37 | a | ) | = | 2880 |
| Left side of the equation = | 35 | ( | 1155 | − | 37 | a | ) | + | a | ( | 1155 | − | 37 | a | ) |
| = | 35 | × | 1155 | − | 35 | × | 37 | a | + | a | ( | 1155 | − | 37 | a | ) |
| = | 40425 | − | 1295 | a | + | a | ( | 1155 | − | 37 | a | ) |
| = | 40425 | − | 1295 | a | + | a | × | 1155 | − | a | × | 37 | a |
| = | 40425 | − | 140 | a | − | a | × | 37 | a |
| 40425 | − | 140 | a | − | a | × | 37 | a | = | 2880 |