| 648 | = | 2000 | × | 3 4 | ( | 1 | − | x | ) | × | 9 10 | ( | 1 | − | 2 | x | ) |
| Right side of the equation = | 1350 | ( | 1 | − | x | ) | ( | 1 | − | 2 | x | ) |
| 648 | = | 1350 | ( | 1 | − | x | ) | ( | 1 | − | 2 | x | ) |
| Right side of the equation = | 1350 | × | 1 | ( | 1 | − | 2 | x | ) | − | 1350 | x | ( | 1 | − | 2 | x | ) |
| = | 1350 | ( | 1 | − | 2 | x | ) | − | 1350 | x | ( | 1 | − | 2 | x | ) |
| = | 1350 | × | 1 | − | 1350 | × | 2 | x | − | 1350 | x | ( | 1 | − | 2 | x | ) |
| = | 1350 | − | 2700 | x | − | 1350 | x | ( | 1 | − | 2 | x | ) |
| = | 1350 | − | 2700 | x | − | 1350 | x | × | 1 | + | 1350 | x | × | 2 | x |
| = | 1350 | − | 2700 | x | − | 1350 | x | + | 2700 | x | x |
| = | 1350 | − | 4050 | x | + | 2700 | x | x |
| 648 | = | 1350 | − | 4050 | x | + | 2700 | x | x |
| x1= | 1 5 |
| x2= | 13 10 |