| ( | 1 | − | x | ) | ( | 1 | − | x | + | 1 10 | ) | = | 1 2 |
| Left side of the equation = | 1 | ( | 1 | − | x | + | 1 10 | ) | − | x | ( | 1 | − | x | + | 1 10 | ) |
| = | 1 | × | 1 | − | 1 | x | + | 1 | × | 1 10 | − | x | ( | 1 | − | x | + | 1 10 | ) |
| = | 1 | − | 1 | x | + | 1 10 | − | x | ( | 1 | − | x | + | 1 10 | ) |
| = | 11 10 | − | 1 | x | − | x | ( | 1 | − | x | + | 1 10 | ) |
| = | 11 10 | − | 1 | x | − | x | × | 1 | + | x | x | − | x | × | 1 10 |
| = | 11 10 | − | 21 10 | x | + | x | x |
11 10 | − | 21 10 | x | + | x | x | = | 1 2 |