| 2 | × | 12 | X | = | 3 | × | 20 | ( | 35 | − | X | ) |
| Left side of the equation = | 24 | X |
| 24 | X | = | 3 | × | 20 | ( | 35 | − | X | ) |
| Right side of the equation = | 60 | ( | 35 | − | X | ) |
| 24 | X | = | 60 | ( | 35 | − | X | ) |
| Right side of the equation = | 60 | × | 35 | − | 60 | X |
| = | 2100 | − | 60 | X |
| 24 | X | = | 2100 | − | 60 | X |
| 24 | X | + | 60 | X | = | 2100 |
| 84 | X | = | 2100 |
| X | = | 2100 | ÷ | 84 |
| = | 2100 | × | 1 84 |
| = | 25 | × | 1 |
| X | = | 25 |