| ( | 1 2 | − | x | ) | ( | 3 5 | − | x | ) | ÷ | 1 5 | = | 136 5 |
| Left side of the equation = | 1 2 | ( | 3 5 | − | x | ) | × | 5 | − | x | ( | 3 5 | − | x | ) | × | 5 |
| = | 5 2 | ( | 3 5 | − | x | ) | − | x | ( | 3 5 | − | x | ) | × | 5 |
| = | 5 2 | × | 3 5 | − | 5 2 | x | − | x | ( | 3 5 | − | x | ) | × | 5 |
| = | 3 2 | − | 5 2 | x | − | x | ( | 3 5 | − | x | ) | × | 5 |
| = | 3 2 | − | 5 2 | x | − | x | × | 3 5 | × | 5 | + | x | x | × | 5 |
| = | 3 2 | − | 5 2 | x | − | x | × | 3 | + | x | x | × | 5 |
| = | 3 2 | − | 11 2 | x | + | x | x | × | 5 |
3 2 | − | 11 2 | x | + | x | x | × | 5 | = | 136 5 |