| ( | x | − | 18 | ) | ( | x | − | 99 | ÷ | 8 | ) | − | 144 | = | 0 |
| Left side of the equation = | x | ( | x | − | 99 | ÷ | 8 | ) | − | 18 | ( | x | − | 99 | ÷ | 8 | ) | − | 144 |
| = | x | x | − | x | × | 99 | ÷ | 8 | − | 18 | ( | x | − | 99 | ÷ | 8 | ) | − | 144 |
| = | x | x | − | x | × | 99 8 | − | 18 | ( | x | − | 99 | ÷ | 8 | ) | − | 144 |
| = | x | x | − | 99 8 | x | − | 18 | x | + | 18 | × | 99 | ÷ | 8 | − | 144 |
| = | x | x | − | 99 8 | x | − | 18 | x | + | 891 4 | − | 144 |
| = | x | x | − | 243 8 | x | + | 315 4 |
| x | x | − | 243 8 | x | + | 315 4 | = | 0 |