| ( | - | 5 | x | + | 150 | ) | ( | x | − | 8 | ) | = | 425 |
| Left side of the equation = | - | 5 | x | ( | x | − | 8 | ) | + | 150 | ( | x | − | 8 | ) |
| = | - | 5 | x | x | + | 5 | x | × | 8 | + | 150 | ( | x | − | 8 | ) |
| = | - | 5 | x | x | + | 40 | x | + | 150 | ( | x | − | 8 | ) |
| = | - | 5 | x | x | + | 40 | x | + | 150 | x | − | 150 | × | 8 |
| = | - | 5 | x | x | + | 40 | x | + | 150 | x | − | 1200 |
| = | - | 5 | x | x | + | 190 | x | − | 1200 |
| - | 5 | x | x | + | 190 | x | − | 1200 | = | 425 |