| ( | X | + | 5 | ) | ÷ | ( | X | + | 100 | ) | = | 7 20 |
| Multiply both sides of the equation by: | ( | X | + | 100 | ) |
| ( | X | + | 5 | ) | = | 7 20 | ( | X | + | 100 | ) |
| X | + | 5 | = | 7 20 | ( | X | + | 100 | ) |
| X | + | 5 | = | 7 20 | X | + | 7 20 | × | 100 |
| X | + | 5 | = | 7 20 | X | + | 35 |
| X | − | 7 20 | X | = | 35 | − | 5 |
13 20 | X | = | 35 | − | 5 |
13 20 | X | = | 30 |
| X | = | 30 | ÷ | 13 20 |
| = | 30 | × | 20 13 |
| X | = | 600 13 |
| X | = | 46.153846 |