| ( | x | + | 1 | ) | ( | x | + | 1 | ) | − | 9 | x | x | = | 0 |
| Left side of the equation = | x | ( | x | + | 1 | ) | + | 1 | ( | x | + | 1 | ) | − | 9 | x | x |
| = | x | x | + | x | × | 1 | + | 1 | ( | x | + | 1 | ) | − | 9 | x | x |
| = | x | x | + | 1 | x | + | 1 | x | + | 1 | × | 1 | − | 9 | x | x |
| = | x | x | + | 1 | x | + | 1 | x | + | 1 | − | 9 | x | x |
| = | x | x | + | 2 | x | + | 1 | − | 9 | x | x |
| x | x | + | 2 | x | + | 1 | − | 9 | x | x | = | 0 |
| x1= | - | 1 4 |
| x2= | 1 2 |