| ( | x | − | 37 | ) | ( | 70 | − | 2 | x | ) | = | 2590 |
| Left side of the equation = | x | ( | 70 | − | 2 | x | ) | − | 37 | ( | 70 | − | 2 | x | ) |
| = | x | × | 70 | − | x | × | 2 | x | − | 37 | ( | 70 | − | 2 | x | ) |
| = | 70 | x | − | x | × | 2 | x | − | 37 | × | 70 | + | 37 | × | 2 | x |
| = | 70 | x | − | x | × | 2 | x | − | 2590 | + | 74 | x |
| = | 144 | x | − | x | × | 2 | x | − | 2590 |
| 144 | x | − | x | × | 2 | x | − | 2590 | = | 2590 |