| 12 | ÷ | ( | 35 | − | 3 | x | ) | + | 18 | ÷ | ( | 34 | − | 3 | x | ) | = | 18 | ÷ | 17 |
| 方程两边同时乘以: | ( | 35 | − | 3 | x | ) |
| 12 | + | 18 | ÷ | ( | 34 | − | 3 | x | ) | × | ( | 35 | − | 3 | x | ) | = | 18 | ÷ | 17 | × | ( | 35 | − | 3 | x | ) |
| 12 | + | 18 | ÷ | ( | 34 | − | 3 | x | ) | × | 35 | − | 18 | ÷ | ( | 34 | − | 3 | x | ) | × | 3 | x | = | 18 | ÷ | 17 | × | ( | 35 | − | 3 | x | ) |
| 12 | + | 18 | ÷ | ( | 34 | − | 3 | x | ) | × | 35 | − | 18 | ÷ | ( | 34 | − | 3 | x | ) | × | 3 | x | = | 18 | ÷ | 17 | × | 35 | − | 18 | ÷ | 17 | × | 3 | x |
| 12 | + | 630 | ÷ | ( | 34 | − | 3 | x | ) | − | 54 | ÷ | ( | 34 | − | 3 | x | ) | × | x | = | 630 17 | − | 54 17 | x |
| 方程两边同时乘以: | ( | 34 | − | 3 | x | ) |
| 12 | ( | 34 | − | 3 | x | ) | + | 630 | − | 54 | x | = | 630 17 | ( | 34 | − | 3 | x | ) | − | 54 17 | x | ( | 34 | − | 3 | x | ) |
| 12 | × | 34 | − | 12 | × | 3 | x | + | 630 | − | 54 | x | = | 630 17 | ( | 34 | − | 3 | x | ) | − | 54 17 | x | ( | 34 | − | 3 | x | ) |
| 12 | × | 34 | − | 12 | × | 3 | x | + | 630 | − | 54 | x | = | 630 17 | × | 34 | − | 630 17 | × | 3 | x | − | 54 17 | x | ( | 34 | − | 3 | x | ) |
| 408 | − | 36 | x | + | 630 | − | 54 | x | = | 1260 | − | 1890 17 | x | − | 54 17 | x | ( | 34 | − | 3 | x | ) |
| 1038 | − | 90 | x | = | 1260 | − | 1890 17 | x | − | 54 17 | x | ( | 34 | − | 3 | x | ) |
| 1038 | − | 90 | x | = | 1260 | − | 1890 17 | x | − | 54 17 | x | × | 34 | + | 54 17 | x | × | 3 | x |
| 1038 | − | 90 | x | = | 1260 | − | 1890 17 | x | − | 108 | x | + | 162 17 | x | x |
| 1038 | − | 90 | x | = | 1260 | − | 3726 17 | x | + | 162 17 | x | x |