| - | 78 | + | 84 | ÷ | ( | 1 | + | X | ÷ | 12 | × | 2 | ) | = | 0 |
| Multiply both sides of the equation by: | ( | 1 | + | X | ÷ | 12 | × | 2 | ) |
| - | 78 | ( | 1 | + | X | ÷ | 12 | × | 2 | ) | + | 84 | = | 0 |
| - | 78 | × | 1 | − | 78 | X | ÷ | 12 | × | 2 | + | 84 | = | 0 |
| - | 78 | − | 13 | X | + | 84 | = | 0 |
| 6 | − | 13 | X | = | 0 |
| - | 13 | X | = | 0 | − | 6 |
| - | 13 | X | = | - | 6 |
| 6 | = | 13 | X |
| 13 | X | = | 6 |
| X | = | 6 | ÷ | 13 |
| = | 6 | × | 1 13 |
| X | = | 6 13 |
| X | = | 0.461538 |