| 20000 | ( | x | + | 1 | ) | × | 10 | ( | 1 | + | 2 | x | ) | = | 60000 |
| 方程左边 = | 200000 | ( | x | + | 1 | ) | ( | 1 | + | 2 | x | ) |
| 200000 | ( | x | + | 1 | ) | ( | 1 | + | 2 | x | ) | = | 60000 |
| 方程左边 = | 200000 | x | ( | 1 | + | 2 | x | ) | + | 200000 | × | 1 | ( | 1 | + | 2 | x | ) |
| = | 200000 | x | ( | 1 | + | 2 | x | ) | + | 200000 | ( | 1 | + | 2 | x | ) |
| = | 200000 | x | × | 1 | + | 200000 | x | × | 2 | x | + | 200000 | ( | 1 | + | 2 | x | ) |
| = | 200000 | x | + | 400000 | x | x | + | 200000 | ( | 1 | + | 2 | x | ) |
| = | 200000 | x | + | 400000 | x | x | + | 200000 | × | 1 | + | 200000 | × | 2 | x |
| = | 200000 | x | + | 400000 | x | x | + | 200000 | + | 400000 | x |
| = | 600000 | x | + | 400000 | x | x | + | 200000 |
| 600000 | x | + | 400000 | x | x | + | 200000 | = | 60000 |