| ( | 100 | + | x | ) | ( | 1000 | − | 2 | x | ) | = | 100000 | × | 144 125 |
| 方程左边 = | 100 | ( | 1000 | − | 2 | x | ) | + | x | ( | 1000 | − | 2 | x | ) |
| = | 100 | × | 1000 | − | 100 | × | 2 | x | + | x | ( | 1000 | − | 2 | x | ) |
| = | 100000 | − | 200 | x | + | x | ( | 1000 | − | 2 | x | ) |
| = | 100000 | − | 200 | x | + | x | × | 1000 | − | x | × | 2 | x |
| = | 100000 | + | 800 | x | − | x | × | 2 | x |
| 100000 | + | 800 | x | − | x | × | 2 | x | = | 100000 | × | 144 125 |
| 方程右边 = | 115200 |
| 100000 | + | 800 | x | − | x | × | 2 | x | = | 115200 |
| ( | x | + | 10 | ) | ( | 80 | − | 2 | x | ) | = | 1200 |
| 方程左边 = | x | ( | 80 | − | 2 | x | ) | + | 10 | ( | 80 | − | 2 | x | ) |
| = | x | × | 80 | − | x | × | 2 | x | + | 10 | ( | 80 | − | 2 | x | ) |
| = | 80 | x | − | x | × | 2 | x | + | 10 | × | 80 | − | 10 | × | 2 | x |
| = | 80 | x | − | x | × | 2 | x | + | 800 | − | 20 | x |
| = | 60 | x | − | x | × | 2 | x | + | 800 |
| 60 | x | − | x | × | 2 | x | + | 800 | = | 1200 |