| ( | x | − | 18 | ) | ( | - | 2 | x | + | 100 | ) | = | 350 |
| Left side of the equation = | x | ( | - | 2 | x | + | 100 | ) | − | 18 | ( | - | 2 | x | + | 100 | ) |
| = | - | x | × | 2 | x | + | x | × | 100 | − | 18 | ( | - | 2 | x | + | 100 | ) |
| = | - | x | × | 2 | x | + | 100 | x | + | 18 | × | 2 | x | − | 18 | × | 100 |
| = | - | x | × | 2 | x | + | 100 | x | + | 36 | x | − | 1800 |
| = | - | x | × | 2 | x | + | 136 | x | − | 1800 |
| - | x | × | 2 | x | + | 136 | x | − | 1800 | = | 350 |