| ( | x | − | 70 | ) | ( | 90 | − | x | ÷ | 2 | ) | = | 14641 100 |
| Left side of the equation = | x | ( | 90 | − | x | ÷ | 2 | ) | − | 70 | ( | 90 | − | x | ÷ | 2 | ) |
| = | x | × | 90 | − | x | x | ÷ | 2 | − | 70 | ( | 90 | − | x | ÷ | 2 | ) |
| = | 90 | x | − | x | x | × | 1 2 | − | 70 | × | 90 | + | 70 | x | ÷ | 2 |
| = | 90 | x | − | x | x | × | 1 2 | − | 6300 | + | 35 | x |
| = | 125 | x | − | x | x | × | 1 2 | − | 6300 |
| 125 | x | − | x | x | × | 1 2 | − | 6300 | = | 14641 100 |