| ( | 2130 | × | 1 20 | ) | − | ( | x | × | 1 20 | ) | = | 100 |
| Left side of the equation = | 2130 | × | 1 20 | − | ( | x | × | 1 20 | ) |
| = | 213 2 | − | ( | x | × | 1 20 | ) |
| = | 213 2 | − | x | × | 1 20 |
213 2 | − | 1 20 | x | = | 100 |
| - | 1 20 | x | = | 100 | − | 213 2 |
| - | 1 20 | x | = | - | 13 2 |
13 2 | = | 1 20 | x |
1 20 | x | = | 13 2 |
| x | = | 13 2 | ÷ | 1 20 |
| = | 13 2 | × | 20 |
| = | 13 | × | 10 |
| x | = | 130 |