| 30 | ÷ | ( | 12 | + | x | ) | + | 30 | ÷ | ( | 12 | − | x | ) | = | 16 | ÷ | 3 |
| 方程两边同时乘以: | ( | 12 | + | x | ) |
| 30 | + | 30 | ÷ | ( | 12 | − | x | ) | × | ( | 12 | + | x | ) | = | 16 | ÷ | 3 | × | ( | 12 | + | x | ) |
| 30 | + | 30 | ÷ | ( | 12 | − | x | ) | × | 12 | + | 30 | ÷ | ( | 12 | − | x | ) | × | x | = | 16 | ÷ | 3 | × | ( | 12 | + | x | ) |
| 30 | + | 30 | ÷ | ( | 12 | − | x | ) | × | 12 | + | 30 | ÷ | ( | 12 | − | x | ) | × | x | = | 16 | ÷ | 3 | × | 12 | + | 16 | ÷ | 3 | × | x |
| 30 | + | 360 | ÷ | ( | 12 | − | x | ) | + | 30 | ÷ | ( | 12 | − | x | ) | × | x | = | 64 | + | 16 3 | x |
| 方程两边同时乘以: | ( | 12 | − | x | ) |
| 30 | ( | 12 | − | x | ) | + | 360 | + | 30 | x | = | 64 | ( | 12 | − | x | ) | + | 16 3 | x | ( | 12 | − | x | ) |
| 30 | × | 12 | − | 30 | x | + | 360 | + | 30 | x | = | 64 | ( | 12 | − | x | ) | + | 16 3 | x | ( | 12 | − | x | ) |
| 30 | × | 12 | − | 30 | x | + | 360 | + | 30 | x | = | 64 | × | 12 | − | 64 | x | + | 16 3 | x | ( | 12 | − | x | ) |
| 360 | − | 30 | x | + | 360 | + | 30 | x | = | 768 | − | 64 | x | + | 16 3 | x | ( | 12 | − | x | ) |
| 720 | − | 0 | x | = | 768 | − | 64 | x | + | 16 3 | x | ( | 12 | − | x | ) |
| 720 | = | 768 | − | 64 | x | + | 16 3 | x | × | 12 | − | 16 3 | x | x |
| 720 | = | 768 | − | 64 | x | + | 64 | x | − | 16 3 | x | x |
| 720 | = | 768 | − | 0 | x | − | 16 3 | x | x |