| 3 | ( | X | + | 4 | ) | = | 5 | − | 2 | ( | X | − | 1 | ) |
| Left side of the equation = | 3 | X | + | 3 | × | 4 |
| = | 3 | X | + | 12 |
| 3 | X | + | 12 | = | 5 | − | 2 | ( | X | − | 1 | ) |
| Right side of the equation = | 5 | − | 2 | X | + | 2 | × | 1 |
| = | 5 | − | 2 | X | + | 2 |
| = | 7 | − | 2 | X |
| 3 | X | + | 12 | = | 7 | − | 2 | X |
| 3 | X | + | 2 | X | = | 7 | − | 12 |
| 5 | X | = | 7 | − | 12 |
| 5 | X | = | - | 5 |
| X | = | - | 5 | ÷ | 5 |
| = | - | 5 | × | 1 5 |
| = | - | 1 | × | 1 |
| X | = | - | 1 |