| ( | 9 10 | − | x | ) | ( | 1 | − | x | ) | ( | 1 | − | x | ) | − | 1 100 | x | = | 0 |
| Left side of the equation = | 9 10 | ( | 1 | − | x | ) | ( | 1 | − | x | ) | − | x | ( | 1 | − | x | ) | ( | 1 | − | x | ) | − | 1 100 | x |
| = | 9 10 | × | 1 | ( | 1 | − | x | ) | − | 9 10 | x | ( | 1 | − | x | ) | − | x | ( | 1 | − | x | ) | ( | 1 | − | x | ) | − | 1 100 | x |
| = | 9 10 | ( | 1 | − | x | ) | − | 9 10 | x | ( | 1 | − | x | ) | − | x | ( | 1 | − | x | ) | ( | 1 | − | x | ) | − | 1 100 | x |
| = | 9 10 | × | 1 | − | 9 10 | x | − | 9 10 | x | ( | 1 | − | x | ) | − | x | ( | 1 | − | x | ) | ( | 1 | − | x | ) | − | 1 100 | x |
| = | 9 10 | − | 9 10 | x | − | 9 10 | x | ( | 1 | − | x | ) | − | x | ( | 1 | − | x | ) | ( | 1 | − | x | ) | − | 1 100 | x |
| = | 9 10 | − | 91 100 | x | − | 9 10 | x | ( | 1 | − | x | ) | − | x | ( | 1 | − | x | ) | ( | 1 | − | x | ) |
| = | 9 10 | − | 91 100 | x | − | 9 10 | x | × | 1 | + | 9 10 | x | x | − | x | ( | 1 | − | x | ) | ( | 1 | − | x | ) |
| = | 9 10 | − | 91 100 | x | − | 9 10 | x | + | 9 10 | x | x | − | x | ( | 1 | − | x | ) | ( | 1 | − | x | ) |
| = | 9 10 | − | 181 100 | x | + | 9 10 | x | x | − | x | ( | 1 | − | x | ) | ( | 1 | − | x | ) |
| = | 9 10 | − | 181 100 | x | + | 9 10 | x | x | − | x | × | 1 | ( | 1 | − | x | ) | + | x | x | ( | 1 | − | x | ) |
| = | 9 10 | − | 181 100 | x | + | 9 10 | x | x | − | x | × | 1 | × | 1 | + | x | × | 1 | x |
| = | 9 10 | − | 181 100 | x | + | 9 10 | x | x | − | x | × | 1 | + | x | × | 1 | x | + | x |
| = | 9 10 | − | 281 100 | x | + | 9 10 | x | x | + | x | × | 1 | x | + | x | x | ( | 1 | − | x | ) |
| = | 9 10 | − | 281 100 | x | + | 9 10 | x | x | + | x | × | 1 | x | + | x | x | × | 1 |
9 10 | − | 281 100 | x | + | 9 10 | x | x | + | x | × | 1 | x | + | x | x | × | 1 | = | 0 |