| ( | 500 | + | 100 | X | ) | ( | 40 | − | X | ) | − | 14000 | − | 300 | X | = | 19500 |
| Left side of the equation = | 500 | ( | 40 | − | X | ) | + | 100 | X | ( | 40 | − | X | ) | − | 14000 | − | 300 | X |
| = | 500 | × | 40 | − | 500 | X | + | 100 | X | ( | 40 | − | X | ) | − | 14000 | − | 300 | X |
| = | 20000 | − | 500 | X | + | 100 | X | ( | 40 | − | X | ) | − | 14000 | − | 300 | X |
| = | 6000 | − | 800 | X | + | 100 | X | ( | 40 | − | X | ) |
| = | 6000 | − | 800 | X | + | 100 | X | × | 40 | − | 100 | X | X |
| = | 6000 | − | 800 | X | + | 4000 | X | − | 100 | X | X |
| = | 6000 | + | 3200 | X | − | 100 | X | X |
| 6000 | + | 3200 | X | − | 100 | X | X | = | 19500 |