| ( | 2 | x | + | 50 | ) | ( | 2 | x | + | 50 | ) | + | ( | 800 | − | 2 | x | ) | ( | 800 | − | 2 | x | ) | = | ( | 4 | x | + | 100 | ) | ( | 4 | x | + | 100 | ) |
| 方程左边 = | 2 | x | ( | 2 | x | + | 50 | ) | + | 50 | ( | 2 | x | + | 50 | ) | + | ( | 800 | − | 2 | x | ) | ( | 800 | − | 2 | x | ) |
| = | 2 | x | × | 2 | x | + | 2 | x | × | 50 | + | 50 | ( | 2 | x | + | 50 | ) | + | ( | 800 | − | 2 | x | ) | ( | 800 | − | 2 | x | ) |
| = | 4 | x | x | + | 100 | x | + | 50 | ( | 2 | x | + | 50 | ) | + | ( | 800 | − | 2 | x | ) | ( | 800 | − | 2 | x | ) |
| = | 4 | x | x | + | 100 | x | + | 50 | × | 2 | x | + | 50 | × | 50 | + | ( | 800 | − | 2 | x | ) | ( | 800 | − | 2 | x | ) |
| = | 4 | x | x | + | 100 | x | + | 100 | x | + | 2500 | + | ( | 800 | − | 2 | x | ) | ( | 800 | − | 2 | x | ) |
| = | 4 | x | x | + | 200 | x | + | 2500 | + | ( | 800 | − | 2 | x | ) | ( | 800 | − | 2 | x | ) |
| = | 4 | x | x | + | 200 | x | + | 2500 | + | 800 | ( | 800 | − | 2 | x | ) | − | 2 | x | ( | 800 | − | 2 | x | ) |
| = | 4 | x | x | + | 200 | x | + | 2500 | + | 800 | × | 800 | − | 800 | × | 2 | x | − | 2 |
| = | 4 | x | x | + | 200 | x | + | 2500 | + | 640000 | − | 1600 | x | − | 2 | x | ( | 800 | − | 2 | x | ) |
| = | 4 | x | x | − | 1400 | x | + | 642500 | − | 2 | x | ( | 800 | − | 2 | x | ) |
| = | 4 | x | x | − | 1400 | x | + | 642500 | − | 2 | x | × | 800 | + | 2 | x | × | 2 |
| = | 4 | x | x | − | 1400 | x | + | 642500 | − | 1600 | x | + | 4 | x | x |
| = | 4 | x | x | − | 3000 | x | + | 642500 | + | 4 | x | x |
| 4 | x | x | − | 3000 | x | + | 642500 | + | 4 | x | x | = | ( | 4 | x | + | 100 | ) | ( | 4 | x | + | 100 | ) |
| 方程右边 = | 4 | x | ( | 4 | x | + | 100 | ) | + | 100 | ( | 4 | x | + | 100 | ) |
| = | 4 | x | × | 4 | x | + | 4 | x | × | 100 | + | 100 | ( | 4 | x | + | 100 | ) |
| = | 16 | x | x | + | 400 | x | + | 100 | ( | 4 | x | + | 100 | ) |
| = | 16 | x | x | + | 400 | x | + | 100 | × | 4 | x | + | 100 | × | 100 |
| = | 16 | x | x | + | 400 | x | + | 400 | x | + | 10000 |
| = | 16 | x | x | + | 800 | x | + | 10000 |
| 4 | x | x | − | 3000 | x | + | 642500 | + | 4 | x | x | = | 16 | x | x | + | 800 | x | + | 10000 |