| ( | x | − | 4 | ) | ( | 110 | − | 5 | x | ) | = | 225 |
| Left side of the equation = | x | ( | 110 | − | 5 | x | ) | − | 4 | ( | 110 | − | 5 | x | ) |
| = | x | × | 110 | − | x | × | 5 | x | − | 4 | ( | 110 | − | 5 | x | ) |
| = | 110 | x | − | x | × | 5 | x | − | 4 | × | 110 | + | 4 | × | 5 | x |
| = | 110 | x | − | x | × | 5 | x | − | 440 | + | 20 | x |
| = | 130 | x | − | x | × | 5 | x | − | 440 |
| 130 | x | − | x | × | 5 | x | − | 440 | = | 225 |