| ( | 288 | + | X | ) | ÷ | ( | 311 | + | X | ) | = | 19 20 |
| Multiply both sides of the equation by: | ( | 311 | + | X | ) |
| ( | 288 | + | X | ) | = | 19 20 | ( | 311 | + | X | ) |
| 288 | + | X | = | 19 20 | ( | 311 | + | X | ) |
| 288 | + | X | = | 19 20 | × | 311 | + | 19 20 | X |
| 288 | + | X | = | 5909 20 | + | 19 20 | X |
| X | − | 19 20 | X | = | 5909 20 | − | 288 |
1 20 | X | = | 5909 20 | − | 288 |
1 20 | X | = | 149 20 |
| X | = | 149 20 | ÷ | 1 20 |
| = | 149 20 | × | 20 |
| = | 149 | × | 1 |
| X | = | 149 |