| ( | 1 | − | 10 100 | ) | ( | 8 | + | x | ) | = | x |
| Left side of the equation = | 1 | ( | 8 | + | x | ) | − | 10 100 | ( | 8 | + | x | ) |
| = | 1 | × | 8 | + | 1 | x | − | 10 100 | ( | 8 | + | x | ) |
| = | 8 | + | 1 | x | − | 10 100 | ( | 8 | + | x | ) |
| = | 8 | + | 1 | x | − | 10 100 | × | 8 | − | 10 100 | x |
| = | 8 | + | 1 | x | − | 4 5 | − | 10 100 | x |
| = | 36 5 | + | 9 10 | x |
36 5 | + | 9 10 | x | = | x |
9 10 | x | − | x | = | - | 36 5 |
| - | 1 10 | x | = | - | 36 5 |
36 5 | = | 1 10 | x |
1 10 | x | = | 36 5 |
| x | = | 36 5 | ÷ | 1 10 |
| = | 36 5 | × | 10 |
| = | 36 | × | 2 |
| x | = | 72 |