| ( | X | − | 219 100 | − | 1 20 | X | ) | ÷ | X | = | 7 20 |
| Multiply both sides of the equation by: | X |
| ( | X | − | 219 100 | − | 1 20 | X | ) | = | 7 20 | X |
| X | − | 219 100 | − | 1 20 | X | = | 7 20 | X |
19 20 | X | − | 219 100 | = | 7 20 | X |
19 20 | X | − | 7 20 | X | = | 219 100 |
3 5 | X | = | 219 100 |
| X | = | 219 100 | ÷ | 3 5 |
| = | 219 100 | × | 5 3 |
| = | 73 20 | × | 1 |
| X | = | 73 20 |
| X | = | 3.65 |