| 20 | ( | ( | X | + | 1 | + | 5 | ÷ | 4 | ) | ÷ | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ) | ÷ | ( | 2 | ÷ | 3 | ) | = | ( | 2 | + | 3 | ) | ( | 3 | ) | ÷ | ( | 1 | ÷ | 3 | ) |
| 方程两边同时乘以: | ( | 2 | ÷ | 3 | ) | , | ( | 1 | ÷ | 3 | ) |
| 20 | ( | ( | X | + | 1 | + | 5 | ÷ | 4 | ) | ÷ | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ) | ( | 1 | ÷ | 3 | ) | = | ( | 2 | + | 3 | ) | ( | 3 | ) | ( | 2 | ÷ | 3 | ) |
| 20 | ( | X | + | 1 | + | 5 | ÷ | 4 | ) | ÷ | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | × | ( | 1 | ÷ | 3 | ) | = | ( | 2 | + | 3 | ) | ( | 3 | ) | ( | 2 | ÷ | 3 | ) |
| 20 | ( | X | + | 1 | + | 5 | ÷ | 4 | ) | ÷ | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | × | ( | 1 | ÷ | 3 | ) | = | 2 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) |
| 方程两边同时乘以: | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
| 20 | ( | X | + | 1 | + | 5 | ÷ | 4 | ) | ( | 1 | ÷ | 3 | ) | = | 2 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
| 20 | X | ( | 1 | ÷ | 3 | ) | + | 20 | × | 1 | ( | 1 | ÷ | 3 | ) | + | 20 | × | 5 | ÷ | 4 | × | ( | 1 | ÷ | 3 | ) | = | 2 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
| 20 | X | ( | 1 | ÷ | 3 | ) | + | 20 | × | 1 | ( | 1 | ÷ | 3 | ) | + | 20 | × | 5 | ÷ | 4 | × | ( | 1 | ÷ | 3 | ) | = | 2 | × | 3 | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
| 20 | X | ( | 1 | ÷ | 3 | ) | + | 20 | ( | 1 | ÷ | 3 | ) | + | 25 | ( | 1 | ÷ | 3 | ) | = | 6 | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
| 20 | X | × | 1 | ÷ | 3 | + | 20 | ( | 1 | ÷ | 3 | ) | + | 25 | ( | 1 | ÷ | 3 | ) | = | 6 | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
| 20 | X | × | 1 | ÷ | 3 | + | 20 | ( | 1 | ÷ | 3 | ) | + | 25 | ( | 1 | ÷ | 3 | ) | = | 6 | × | 2 | ÷ | 3 | × | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
20 3 | X | + | 20 | ( | 1 | ÷ | 3 | ) | + | 25 | ( | 1 | ÷ | 3 | ) | = | 4 | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
20 3 | X | + | 20 | × | 1 | ÷ | 3 | + | 25 | ( | 1 | ÷ | 3 | ) | = | 4 | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
20 3 | X | + | 20 | × | 1 | ÷ | 3 | + | 25 | ( | 1 | ÷ | 3 | ) | = | 4 | × | 2 | ÷ | ( | 2 | ÷ | 5 | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
20 3 | X | + | 20 3 | + | 25 | ( | 1 | ÷ | 3 | ) | = | 8 | ÷ | ( | 2 | ÷ | 5 | ) | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) |
| 方程两边同时乘以: | ( | 2 | ÷ | 5 | ) |
20 3 | X | ( | 2 | ÷ | 5 | ) | + | 20 3 | ( | 2 | ÷ | 5 | ) | + | 25 | ( | 1 | ÷ | 3 | ) | ( | 2 | ÷ | 5 | ) | = | 8 | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ( | 2 | ÷ | 5 | ) |
20 3 | X | × | 2 | ÷ | 5 | + | 20 3 | ( | 2 | ÷ | 5 | ) | + | 25 | ( | 1 | ÷ | 3 | ) | ( | 2 | ÷ | 5 | ) | = | 8 | + | 3 | ( | 3 | ) | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ( | 2 | ÷ | 5 | ) |
20 3 | X | × | 2 | ÷ | 5 | + | 20 3 | ( | 2 | ÷ | 5 | ) | + | 25 | ( | 1 | ÷ | 3 | ) | ( | 2 | ÷ | 5 | ) | = | 8 | + | 3 | × | 3 | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ( | 2 | ÷ | 5 | ) |
8 3 | X | + | 20 3 | ( | 2 | ÷ | 5 | ) | + | 25 | ( | 1 | ÷ | 3 | ) | ( | 2 | ÷ | 5 | ) | = | 8 | + | 9 | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ( | 2 | ÷ | 5 | ) |
8 3 | X | + | 20 3 | × | 2 | ÷ | 5 | + | 25 | ( | 1 | ÷ | 3 | ) | ( | 2 | ÷ | 5 | ) | = | 8 | + | 9 | ( | 2 | ÷ | 3 | ) | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ( | 2 | ÷ | 5 | ) |
8 3 | X | + | 20 3 | × | 2 | ÷ | 5 | + | 25 | ( | 1 | ÷ | 3 | ) | ( | 2 | ÷ | 5 | ) | = | 8 | + | 9 | × | 2 | ÷ | 3 | × | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ( | 2 | ÷ | 5 | ) |
8 3 | X | + | 8 3 | + | 25 | ( | 1 | ÷ | 3 | ) | ( | 2 | ÷ | 5 | ) | = | 8 | + | 6 | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ( | 2 | ÷ | 5 | ) |
8 3 | X | + | 8 3 | + | 25 | × | 1 | ÷ | 3 | × | ( | 2 | ÷ | 5 | ) | = | 8 | + | 6 | ( | 2 | ÷ | ( | 2 | ÷ | 5 | ) | ) | ( | 2 | ÷ | 5 | ) |
8 3 | X | + | 8 3 | + | 25 | × | 1 | ÷ | 3 | × | ( | 2 | ÷ | 5 | ) | = | 8 | + | 6 | × | 2 | ÷ | ( | 2 | ÷ | 5 | ) | × | ( | 2 | ÷ | 5 | ) |