| 4024 | = | 2 | ( | 500 | − | 40 | ) | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| 方程右边 = | 2 | × | 500 | x | − | 2 | × | 40 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 1000 | x | − | 80 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 920 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 920 | x | + | 2 | × | 250 | x | − | 2 | × | 40 | x | − | 2 | × | 2 | x | x |
| = | 920 | x | + | 500 | x | − | 80 | x | − | 4 | x | x |
| = | 1340 | x | − | 4 | x | x |
| 4024 | = | 1340 | x | − | 4 | x | x |
| 2687 | = | 2 | ( | 500 | − | 40 | ) | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| 方程右边 = | 2 | × | 500 | x | − | 2 | × | 40 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 1000 | x | − | 80 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 920 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 920 | x | + | 2 | × | 250 | x | − | 2 | × | 40 | x | − | 2 | × | 2 | x | x |
| = | 920 | x | + | 500 | x | − | 80 | x | − | 4 | x | x |
| = | 1340 | x | − | 4 | x | x |
| 2687 | = | 1340 | x | − | 4 | x | x |
| 1138 | = | 2 | ( | 500 | − | 40 | ) | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| 方程右边 = | 2 | × | 500 | x | − | 2 | × | 40 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 1000 | x | − | 80 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 920 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 920 | x | + | 2 | × | 250 | x | − | 2 | × | 40 | x | − | 2 | × | 2 | x | x |
| = | 920 | x | + | 500 | x | − | 80 | x | − | 4 | x | x |
| = | 1340 | x | − | 4 | x | x |
| 1138 | = | 1340 | x | − | 4 | x | x |
| 1780 | = | 2 | ( | 500 | − | 40 | ) | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| 方程右边 = | 2 | × | 500 | x | − | 2 | × | 40 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 1000 | x | − | 80 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 920 | x | + | 2 | ( | 250 | − | 40 | − | 2 | x | ) | x |
| = | 920 | x | + | 2 | × | 250 | x | − | 2 | × | 40 | x | − | 2 | × | 2 | x | x |
| = | 920 | x | + | 500 | x | − | 80 | x | − | 4 | x | x |
| = | 1340 | x | − | 4 | x | x |
| 1780 | = | 1340 | x | − | 4 | x | x |