| 75 | × | 26 | = | ( | 76 | + | x | ) | ( | x | − | 75 | ) | ÷ | 2 |
| 方程左边 = | 1950 |
| 1950 | = | ( | 76 | + | x | ) | ( | x | − | 75 | ) | ÷ | 2 |
| 方程右边 = | 76 | ( | x | − | 75 | ) | × | 1 2 | + | x | ( | x | − | 75 | ) | × | 1 2 |
| = | 38 | ( | x | − | 75 | ) | + | x | ( | x | − | 75 | ) | × | 1 2 |
| = | 38 | x | − | 38 | × | 75 | + | x | ( | x | − | 75 | ) | × | 1 2 |
| = | 38 | x | − | 2850 | + | x | ( | x | − | 75 | ) | × | 1 2 |
| = | 38 | x | − | 2850 | + | x | x | × | 1 2 | − | x | × | 75 | × | 1 2 |
| = | 38 | x | − | 2850 | + | x | x | × | 1 2 | − | x | × | 75 2 |
| = | 1 2 | x | − | 2850 | + | x | x | × | 1 2 |
| 1950 | = | 1 2 | x | − | 2850 | + | x | x | × | 1 2 |