| - | x | × | 15 | + | 660 | ( | 171 5 | ÷ | 2 | + | 15 | ) | − | x | ( | 171 5 | + | 15 | ) | − | ( | 330 | − | x | ) | ( | 171 5 | + | 15 | × | 2 | ) | = | 0 |
| Left side of the equation = | - | 15 | x | + | 660 | × | 171 5 | ÷ | 2 | + | 660 | × | 15 | − | x | ( | 171 5 | + | 15 | ) | − | ( | 330 | − | x | ) | ( | 171 5 | + | 15 | × | 2 | ) |
| = | - | 15 | x | + | 11286 | + | 9900 | − | x | ( | 171 5 | + | 15 | ) | − | ( | 330 | − | x | ) | ( | 171 5 | + | 15 | × | 2 | ) |
| = | - | 15 | x | + | 21186 | − | x | ( | 171 5 | + | 15 | ) | − | ( | 330 | − | x | ) | ( | 171 5 | + | 15 | × | 2 | ) |
| = | - | 15 | x | + | 21186 | − | x | × | 171 5 | − | x | × | 15 | − | ( | 330 | − | x | ) | ( | 171 5 | + | 15 | × | 2 | ) |
| = | - | 321 5 | x | + | 21186 | − | ( | 330 | − | x | ) | ( | 171 5 | + | 15 | × | 2 | ) |
| = | - | 321 5 | x | + | 21186 | − | 330 | ( | 171 5 | + | 15 | × | 2 | ) | + | x | ( | 171 5 | + | 15 | × | 2 | ) |
| = | - | 321 5 | x | + | 21186 | − | 330 | × | 171 5 | − | 330 | × | 15 | × | 2 | + | x | ( | 171 5 | + | 15 | × | 2 | ) |
| = | - | 321 5 | x | + | 21186 | − | 11286 | − | 9900 | + | x | ( | 171 5 | + | 15 | × | 2 | ) |
| = | - | 321 5 | x | + | 0 | + | x | ( | 171 5 | + | 15 | × | 2 | ) |
| = | - | 321 5 | x | + | 0 | + | x | × | 171 5 | + | x | × | 15 | × | 2 |
| = | - | 321 5 | x | + | 0 | + | x | × | 171 5 | + | x | × | 30 |
| = | - | 0 | x | + | 0 |
| - | 0 | x | + | 0 | = | 0 |
| = | 0 | − | 0 |