| ( | 169 | + | X | ) | ÷ | ( | 207 | + | X | ) | = | 1 5 |
| Multiply both sides of the equation by: | ( | 207 | + | X | ) |
| ( | 169 | + | X | ) | = | 1 5 | ( | 207 | + | X | ) |
| 169 | + | X | = | 1 5 | ( | 207 | + | X | ) |
| 169 | + | X | = | 1 5 | × | 207 | + | 1 5 | X |
| 169 | + | X | = | 207 5 | + | 1 5 | X |
| X | − | 1 5 | X | = | 207 5 | − | 169 |
4 5 | X | = | 207 5 | − | 169 |
4 5 | X | = | - | 638 5 |
| X | = | - | 638 5 | ÷ | 4 5 |
| = | - | 638 5 | × | 5 4 |
| = | - | 319 | × | 1 2 |
| X | = | - | 319 2 |
| X | = | - 159.5 |