| 43 | x | − | x | ( | x | − | 1 | ) | × | 13 10 | ÷ | 2 | = | 500 |
| Left side of the equation = | 43 | x | − | x | ( | x | − | 1 | ) | × | 13 20 |
| 43 | x | − | x | ( | x | − | 1 | ) | × | 13 20 | = | 500 |
| Left side of the equation = | 43 | x | − | x | x | × | 13 20 | + | x | × | 1 | × | 13 20 |
| = | 43 | x | − | x | x | × | 13 20 | + | x | × | 13 20 |
| = | 873 20 | x | − | x | x | × | 13 20 |
873 20 | x | − | x | x | × | 13 20 | = | 500 |