| 12 | = | X | × | 1 2 | ( | 37 2 | − | X | − | 1 2 | ) | ÷ | 2 |
| Right side of the equation = | X | × | 1 4 | ( | 37 2 | − | X | − | 1 2 | ) |
| 12 | = | X | × | 1 4 | ( | 37 2 | − | X | − | 1 2 | ) |
| Right side of the equation = | X | × | 1 4 | × | 37 2 | − | X | × | 1 4 | X | − | X | × | 1 4 | × | 1 2 |
| = | X | × | 37 8 | − | X | × | 1 4 | X | − | X | × | 1 8 |
| = | 9 2 | X | − | X | × | 1 4 | X |
| 12 | = | 9 2 | X | − | X | × | 1 4 | X |