| ( | x | − | 20 | ) | ( | 350 | − | 5 | x | ) | = | 2625 |
| Left side of the equation = | x | ( | 350 | − | 5 | x | ) | − | 20 | ( | 350 | − | 5 | x | ) |
| = | x | × | 350 | − | x | × | 5 | x | − | 20 | ( | 350 | − | 5 | x | ) |
| = | 350 | x | − | x | × | 5 | x | − | 20 | × | 350 | + | 20 | × | 5 | x |
| = | 350 | x | − | x | × | 5 | x | − | 7000 | + | 100 | x |
| = | 450 | x | − | x | × | 5 | x | − | 7000 |
| 450 | x | − | x | × | 5 | x | − | 7000 | = | 2625 |