| 500 | ( | 1 | − | x | ) | ( | 1 | − | 2 | x | ) | = | 240 |
| Left side of the equation = | 500 | × | 1 | ( | 1 | − | 2 | x | ) | − | 500 | x | ( | 1 | − | 2 | x | ) |
| = | 500 | ( | 1 | − | 2 | x | ) | − | 500 | x | ( | 1 | − | 2 | x | ) |
| = | 500 | × | 1 | − | 500 | × | 2 | x | − | 500 | x | ( | 1 | − | 2 | x | ) |
| = | 500 | − | 1000 | x | − | 500 | x | ( | 1 | − | 2 | x | ) |
| = | 500 | − | 1000 | x | − | 500 | x | × | 1 | + | 500 | x | × | 2 | x |
| = | 500 | − | 1000 | x | − | 500 | x | + | 1000 | x | x |
| = | 500 | − | 1500 | x | + | 1000 | x | x |
| 500 | − | 1500 | x | + | 1000 | x | x | = | 240 |
| x1= | 1 5 |
| x2= | 13 10 |