| 6 | = | - | ( | 1 | ÷ | 40 | ) | ( | x | − | 20 | ) | ( | x | − | 20 | ) | + | 10 |
| Right side of the equation = | - | 1 | ÷ | 40 | × | ( | x | − | 20 | ) | ( | x | − | 20 | ) | + | 10 |
| = | - | 1 40 | ( | x | − | 20 | ) | ( | x | − | 20 | ) | + | 10 |
| = | - | 1 40 | x | ( | x | − | 20 | ) | + | 1 40 | × | 20 | ( | x | − | 20 | ) | + | 10 |
| = | - | 1 40 | x | ( | x | − | 20 | ) | + | 1 2 | ( | x | − | 20 | ) | + | 10 |
| = | - | 1 40 | x | x | + | 1 40 | x | × | 20 | + | 1 2 | ( | x | − | 20 | ) | + | 10 |
| = | - | 1 40 | x | x | + | 1 2 | x | + | 1 2 | ( | x | − | 20 | ) | + | 10 |
| = | - | 1 40 | x | x | + | 1 2 | x | + | 1 2 | x | − | 1 2 | × | 20 | + | 10 |
| = | - | 1 40 | x | x | + | 1 2 | x | + | 1 2 | x | − | 10 | + | 10 |
| = | - | 1 40 | x | x | + | 1 | x | − | 0 |
| 6 | = | - | 1 40 | x | x | + | 1 | x |