| ( | X | − | 8 | ) | ( | - | 3 | X | + | 216 | ) | = | 0 |
| Left side of the equation = | X | ( | - | 3 | X | + | 216 | ) | − | 8 | ( | - | 3 | X | + | 216 | ) |
| = | - | X | × | 3 | X | + | X | × | 216 | − | 8 | ( | - | 3 | X | + | 216 | ) |
| = | - | X | × | 3 | X | + | 216 | X | + | 8 | × | 3 | X | − | 8 | × | 216 |
| = | - | X | × | 3 | X | + | 216 | X | + | 24 | X | − | 1728 |
| = | - | X | × | 3 | X | + | 240 | X | − | 1728 |
| - | X | × | 3 | X | + | 240 | X | − | 1728 | = | 0 |