| ( | I | − | 10 100 | ) | ÷ | ( | 12 100 | − | 10 100 | ) | = | ( | 0 | − | 100 | ) | ÷ | ( | - | 20 | − | 100 | ) |
| Multiply both sides of the equation by: | ( | 12 100 | − | 10 100 | ) | , | ( | - | 20 | − | 100 | ) |
| ( | I | − | 10 100 | ) | ( | - | 20 | − | 100 | ) | = | ( | 0 | − | 100 | ) | ( | 12 100 | − | 10 100 | ) |
| I | ( | - | 20 | − | 100 | ) | − | 10 100 | ( | - | 20 | − | 100 | ) | = | ( | 0 | − | 100 | ) | ( | 12 100 | − | 10 100 | ) |
| I | ( | - | 20 | − | 100 | ) | − | 10 100 | ( | - | 20 | − | 100 | ) | = | 0 | ( | 12 100 | − | 10 100 | ) | − | 100 | ( | 12 100 | − | 10 100 | ) |
| - | I | × | 20 | − | I | × | 100 | − | 10 100 | ( | - | 20 | − | 100 | ) | = | 0 | ( | 12 100 | − | 10 100 | ) | − | 100 | ( | 12 100 | − | 10 100 | ) |
| - | I | × | 20 | − | I | × | 100 | − | 10 100 | ( | - | 20 | − | 100 | ) | = | 0 | × | 12 100 | − | 0 | × | 10 100 | − | 100 | ( | 12 100 | − | 10 100 | ) |
| - | I | × | 20 | − | I | × | 100 | − | 10 100 | ( | - | 20 | − | 100 | ) | = | 0 | − | 0 | − | 100 | ( | 12 100 | − | 10 100 | ) |
| - | 120 | I | − | 10 100 | ( | - | 20 | − | 100 | ) | = | 0 | − | 100 | ( | 12 100 | − | 10 100 | ) |
| - | 120 | I | + | 10 100 | × | 20 | + | 10 100 | × | 100 | = | - | 100 | ( | 12 100 | − | 10 100 | ) |
| - | 120 | I | + | 10 100 | × | 20 | + | 10 100 | × | 100 | = | - | 100 | × | 12 100 | + | 100 | × | 10 100 |
| - | 120 | I | + | 2 | + | 10 | = | - | 12 | + | 10 |
| - | 120 | I | + | 12 | = | - | 2 |
| - | 120 | I | = | - | 2 | − | 12 |
| - | 120 | I | = | - | 14 |
| 14 | = | 120 | I |
| 120 | I | = | 14 |
| I | = | 14 | ÷ | 120 |
| = | 14 | × | 1 120 |
| = | 7 | × | 1 60 |
| I | = | 7 60 |
| I | = | 0.116667 |