| 1 | + | x | = | ( | 1 | + | 1 5 | x | ) | ( | 1 | + | 1 5 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) |
| 方程右边 = | 1 | ( | 1 | + | 1 5 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 5 | x | ( | 1 | + | 1 5 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) |
| = | 1 | × | 1 | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 | × | 1 5 | x | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) |
| = | 1 | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 5 | x | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 5 |
| = | 1 | × | 1 | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 | × | 1 20 | x | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 5 |
| = | 1 | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 5 | x | ( | 1 | + | 1 20 | x | ) |
| = | 1 | × | 1 | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 | × | 1 20 | x | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x | ( | 1 | + | 1 20 | x | ) |
| = | 1 | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x | ( | 1 | + | 1 20 | x | ) | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) |
| = | 1 | × | 1 | ( | 1 | + | 7 10 | x | ) | + | 1 | × | 3 10 | x | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 20 |
| = | 1 | ( | 1 | + | 7 10 | x | ) | + | 3 10 | x | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x | ( | 1 | + | 1 20 | x | ) |
| = | 1 | × | 1 | + | 1 | × | 7 10 | x | + | 3 10 | x | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) |
| = | 1 | + | 7 10 | x | + | 3 10 | x | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x |
| = | 1 | + | 7 10 | x | + | 3 10 | x | × | 1 | + | 3 10 | x | × | 7 10 | x | + | 1 20 | x |
| = | 1 | + | 7 10 | x | + | 3 10 | x | + | 21 100 | x | x | + | 1 20 | x | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) |
| = | 1 | + | 1 | x | + | 21 100 | x | x | + | 1 20 | x | ( | 1 | + | 3 10 | x | ) | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x |
| = | 1 | + | 1 | x | + | 21 100 | x | x | + | 1 20 | x | × | 1 | ( | 1 | + | 7 10 | x | ) | + | 1 20 | x |
| = | 1 | + | 1 | x | + | 21 100 | x | x | + | 1 20 | x | ( | 1 | + | 7 10 | x | ) | + | 3 200 | x | x |
| = | 1 | + | 1 | x | + | 21 100 | x | x | + | 1 20 | x | × | 1 | + | 1 20 | x | × | 7 10 |
| = | 1 | + | 1 | x | + | 21 100 | x | x | + | 1 20 | x | + | 7 200 | x | x | + | 3 200 |
| = | 1 | + | 21 20 | x | + | 21 100 | x | x | + | 7 200 | x | x | + | 3 200 | x | x |
| = | 1 | + | 21 20 | x | + | 21 100 | x | x | + | 7 200 | x | x | + | 3 200 | x | x |
| = | 1 | + | 21 20 | x | + | 21 100 | x | x | + | 7 200 | x | x | + | 3 200 | x | x |
| = | 1 | + | 21 20 | x | + | 21 100 | x | x | + | 7 200 | x | x | + | 3 200 | x | x |
| = | 1 | + | 21 20 | x | + | 21 100 | x | x | + | 7 200 | x | x | + | 3 200 | x | x |
| = | 1 | + | 21 20 | x | + | 21 100 | x | x | + | 7 200 | x | x | + | 3 200 | x | x |
| = | 1 | + | 21 20 | x | + | 21 100 | x | x | + | 7 200 | x | x | + | 3 200 | x | x |
| x1=0 |