| ( | x | − | 2500 | ) | ( | x | − | 2500 | ) | × | 50 | ÷ | 8 | = | 5000 |
| 方程左边 = | ( | x | − | 2500 | ) | ( | x | − | 2500 | ) | × | 25 4 |
| ( | x | − | 2500 | ) | ( | x | − | 2500 | ) | × | 25 4 | = | 5000 |
| 方程左边 = | x | ( | x | − | 2500 | ) | × | 25 4 | − | 2500 | ( | x | − | 2500 | ) | × | 25 4 |
| = | x | ( | x | − | 2500 | ) | × | 25 4 | − | 15625 | ( | x | − | 2500 | ) |
| = | x | x | × | 25 4 | − | x | × | 2500 | × | 25 4 | − | 15625 | ( | x | − | 2500 | ) |
| = | x | x | × | 25 4 | − | x | × | 15625 | − | 15625 | ( | x | − | 2500 | ) |
| = | x | x | × | 25 4 | − | 15625 | x | − | 15625 | x | + | 15625 | × | 2500 |
| = | x | x | × | 25 4 | − | 15625 | x | − | 15625 | x | + | 39062500 |
| = | x | x | × | 25 4 | − | 31250 | x | + | 39062500 |
| x | x | × | 25 4 | − | 31250 | x | + | 39062500 | = | 5000 |