| ( | x | − | 105 | ) | ÷ | 100 | = | ( | x | − | 104 | ) | ÷ | 104 |
| Left side of the equation = | x | × | 1 100 | − | 105 | × | 1 100 |
| = | x | × | 1 100 | − | 21 20 |
1 100 | x | − | 21 20 | = | ( | x | − | 104 | ) | ÷ | 104 |
| Right side of the equation = | x | × | 1 104 | − | 104 | × | 1 104 |
| = | x | × | 1 104 | − | 1 |
1 100 | x | − | 21 20 | = | 1 104 | x | − | 1 |
1 100 | x | − | 1 104 | x | = | - | 1 | + | 21 20 |
1 2600 | x | = | - | 1 | + | 21 20 |
1 2600 | x | = | 1 20 |
| x | = | 1 20 | ÷ | 1 2600 |
| = | 1 20 | × | 2600 |
| = | 1 | × | 130 |
| x | = | 130 |