| ( | 8 | − | 2 | x | ) | ( | 5 | − | 2 | x | ) | x | = | 0 |
| Left side of the equation = | 8 | ( | 5 | − | 2 | x | ) | x | − | 2 | x | ( | 5 | − | 2 | x | ) | x |
| = | 8 | × | 5 | x | − | 8 | × | 2 | x | x | − | 2 | x | ( | 5 | − | 2 | x | ) | x |
| = | 40 | x | − | 16 | x | x | − | 2 | x | ( | 5 | − | 2 | x | ) | x |
| = | 40 | x | − | 16 | x | x | − | 2 | x | × | 5 | x | + | 2 | x | × | 2 |
| = | 40 | x | − | 16 | x | x | − | 10 | x | x | + | 4 | x | x | x |
| 40 | x | − | 16 | x | x | − | 10 | x | x | + | 4 | x | x | x | = | 0 |
| x2= | 5 2 |
| x3=4 |