| 40 | ÷ | ( | ( | 1 | ÷ | ( | 1 | ÷ | 3 | ) | ) | + | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) | ) | ÷ | ( | 1 | ÷ | 2 | ) | = | x |
| 方程两边同时乘以: | ( | ( | 1 | ÷ | ( | 1 | ÷ | 3 | ) | ) | + | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) | ) |
| 40 | ÷ | ( | 1 | ÷ | 2 | ) | = | x | ( | ( | 1 | ÷ | ( | 1 | ÷ | 3 | ) | ) | + | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) | ) |
| 40 | ÷ | ( | 1 | ÷ | 2 | ) | = | x | ( | 1 | ÷ | ( | 1 | ÷ | 3 | ) | ) | + | x | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) |
| 方程两边同时乘以: | ( | 1 | ÷ | 2 | ) |
| 40 | = | x | ( | 1 | ÷ | ( | 1 | ÷ | 3 | ) | ) | ( | 1 | ÷ | 2 | ) | + | x | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) | ( | 1 | ÷ | 2 | ) |
| 40 | = | x | × | 1 | ÷ | ( | 1 | ÷ | 3 | ) | × | ( | 1 | ÷ | 2 | ) | + | x | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) | ( | 1 | ÷ | 2 | ) |
| 方程两边同时乘以: | ( | 1 | ÷ | 3 | ) |
| 40 | ( | 1 | ÷ | 3 | ) | = | x | × | 1 | ( | 1 | ÷ | 2 | ) | + | x | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) | ( | 1 | ÷ | 2 | ) | ( | 1 | ÷ | 3 | ) |
| 40 | × | 1 | ÷ | 3 | = | x | × | 1 | ( | 1 | ÷ | 2 | ) | + | x | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) | ( | 1 | ÷ | 2 | ) | ( | 1 | ÷ | 3 | ) |
| 40 | × | 1 | ÷ | 3 | = | x | × | 1 | × | 1 | ÷ | 2 | + | x | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) | ( | 1 | ÷ | 2 | ) | ( | 1 | ÷ | 3 | ) |
40 3 | = | x | × | 1 2 | + | x | ( | 1 | ÷ | ( | 1 | ÷ | 2 | ) | ) | ( | 1 | ÷ | 2 | ) | ( | 1 | ÷ | 3 | ) |
40 3 | = | 1 2 | x | + | x | × | 1 | ÷ | ( | 1 | ÷ | 2 | ) | × | ( | 1 | ÷ | 2 | ) | ( | 1 | ÷ | 3 | ) |
| 方程两边同时乘以: | ( | 1 | ÷ | 2 | ) |
40 3 | ( | 1 | ÷ | 2 | ) | = | 1 2 | x | ( | 1 | ÷ | 2 | ) | + | x | × | 1 | ( | 1 | ÷ | 2 | ) | ( | 1 | ÷ | 3 | ) |
40 3 | × | 1 | ÷ | 2 | = | 1 2 | x | ( | 1 | ÷ | 2 | ) | + | x | × | 1 | ( | 1 | ÷ | 2 | ) | ( | 1 | ÷ | 3 | ) |
40 3 | × | 1 | ÷ | 2 | = | 1 2 | x | × | 1 | ÷ | 2 | + | x | × | 1 | ( | 1 | ÷ | 2 | ) | ( | 1 | ÷ | 3 | ) |
20 3 | = | 1 4 | x | + | x | × | 1 | ( | 1 | ÷ | 2 | ) | ( | 1 | ÷ | 3 | ) |
20 3 | = | 1 4 | x | + | x | × | 1 | × | 1 | ÷ | 2 | × | ( | 1 | ÷ | 3 | ) |
20 3 | = | 1 4 | x | + | x | × | 1 2 | ( | 1 | ÷ | 3 | ) |
20 3 | = | 1 4 | x | + | x | × | 1 2 | × | 1 | ÷ | 3 |
20 3 | = | 1 4 | x | + | x | × | 1 6 |
20 3 | = | 5 12 | x |
| - | 5 12 | x | = | - | 20 3 |
20 3 | = | 5 12 | x |
5 12 | x | = | 20 3 |
| x | = | 20 3 | ÷ | 5 12 |
| = | 20 3 | × | 12 5 |
| = | 4 | × | 4 |
| x | = | 16 |