| 27 | x | + | 27 20 | x | ( | 9 | − | x | ) | = | 27 | ( | 9 | − | x | ) |
| Left side of the equation = | 27 | x | + | 27 20 | x | × | 9 | − | 27 20 | x | x |
| = | 27 | x | + | 243 20 | x | − | 27 20 | x | x |
| = | 783 20 | x | − | 27 20 | x | x |
783 20 | x | − | 27 20 | x | x | = | 27 | ( | 9 | − | x | ) |
| Right side of the equation = | 27 | × | 9 | − | 27 | x |
| = | 243 | − | 27 | x |
783 20 | x | − | 27 20 | x | x | = | 243 | − | 27 | x |