| 12 | = | ( | 27 | − | 3 2 | x | ) | ( | 19 | ÷ | ( | 4 | − | x | ) | ) | − | 9 2 | x |
| 12 | = | 27 | ( | 19 | ÷ | ( | 4 | − | x | ) | ) | − | 3 2 | x | ( | 19 | ÷ | ( | 4 | − | x | ) | ) | − | 9 2 | x |
| 12 | = | 27 | × | 19 | ÷ | ( | 4 | − | x | ) | − | 3 2 | x | ( | 19 | ÷ | ( | 4 | − | x | ) | ) | − | 9 2 | x |
| 12 | = | 513 | ÷ | ( | 4 | − | x | ) | − | 3 2 | x | ( | 19 | ÷ | ( | 4 | − | x | ) | ) | − | 9 2 | x |
| 方程两边同时乘以: | ( | 4 | − | x | ) |
| 12 | ( | 4 | − | x | ) | = | 513 | − | 3 2 | x | ( | 19 | ÷ | ( | 4 | − | x | ) | ) | ( | 4 | − | x | ) | − | 9 2 | x | ( | 4 | − | x | ) |
| 12 | × | 4 | − | 12 | x | = | 513 | − | 3 2 | x | ( | 19 | ÷ | ( | 4 | − | x | ) | ) | ( | 4 | − | x | ) | − | 9 2 | x | ( | 4 | − | x | ) |
| 12 | × | 4 | − | 12 | x | = | 513 | − | 3 2 | x | × | 19 | ÷ | ( | 4 | − | x | ) | × | ( | 4 | − | x | ) | − | 9 2 | x | ( | 4 | − | x | ) |
| 48 | − | 12 | x | = | 513 | − | 57 2 | x | ÷ | ( | 4 | − | x | ) | × | ( | 4 | − | x | ) | − | 9 2 | x | ( | 4 | − | x | ) |
| 方程两边同时乘以: | ( | 4 | − | x | ) |
| 48 | ( | 4 | − | x | ) | − | 12 | x | ( | 4 | − | x | ) | = | 513 | ( | 4 | − | x | ) | − | 57 2 | x | ( | 4 | − | x | ) | − | 9 2 | x | ( | 4 | − | x | ) | ( | 4 | − | x | ) |
| 48 | × | 4 | − | 48 | x | − | 12 | x | ( | 4 | − | x | ) | = | 513 | ( | 4 | − | x | ) | − | 57 2 | x | ( | 4 | − | x | ) | − | 9 2 | x | ( | 4 | − | x | ) | ( | 4 | − | x | ) |
| 48 | × | 4 | − | 48 | x | − | 12 | x | ( | 4 | − | x | ) | = | 513 | × | 4 | − | 513 | x | − | 57 2 | x | ( | 4 | − | x | ) | − | 9 2 | x | ( | 4 | − | x | ) | ( | 4 | − | x | ) |
| 192 | − | 48 | x | − | 12 | x | ( | 4 | − | x | ) | = | 2052 | − | 513 | x | − | 57 2 | x | ( | 4 | − | x | ) | − | 9 2 | x | ( | 4 | − | x | ) | ( | 4 | − | x | ) |
| 192 | − | 48 | x | − | 12 | x | × | 4 | + | 12 | x | x | = | 2052 | − | 513 | x | − | 57 2 | x | ( | 4 | − | x | ) | − | 9 2 | x | ( | 4 | − | x | ) | ( | 4 | − | x | ) |
| 192 | − | 48 | x | − | 12 | x | × | 4 | + | 12 | x | x | = | 2052 | − | 513 | x | − | 57 2 | x | × | 4 | + | 57 2 | x | x | − | 9 2 | x | ( | 4 | − | x | ) |
| 192 | − | 48 | x | − | 48 | x | + | 12 | x | x | = | 2052 | − | 513 | x | − | 114 | x | + | 57 2 | x | x | − | 9 2 | x | ( | 4 | − | x | ) | ( | 4 | − | x | ) |
| 192 | − | 96 | x | + | 12 | x | x | = | 2052 | − | 627 | x | + | 57 2 | x | x | − | 9 2 | x | ( | 4 | − | x | ) | ( | 4 | − | x | ) |
| 192 | − | 96 | x | + | 12 | x | x | = | 2052 | − | 627 | x | + | 57 2 | x | x | − | 9 2 | x | × | 4 | ( | 4 | − | x | ) | + | 9 2 | x |
| 192 | − | 96 | x | + | 12 | x | x | = | 2052 | − | 627 | x | + | 57 2 | x | x | − | 18 | x | ( | 4 | − | x | ) | + | 9 2 | x | x |
| 192 | − | 96 | x | + | 12 | x | x | = | 2052 | − | 627 | x | + | 57 2 | x | x | − | 18 | x | × | 4 | + | 18 | x | x |
| 192 | − | 96 | x | + | 12 | x | x | = | 2052 | − | 627 | x | + | 57 2 | x | x | − | 72 | x | + | 18 | x | x | + | 9 2 |
| 192 | − | 96 | x | + | 12 | x | x | = | 2052 | − | 699 | x | + | 57 2 | x | x | + | 18 | x | x | + | 9 2 | x | x |
| 192 | − | 96 | x | + | 12 | x | x | = | 2052 | − | 699 | x | + | 57 2 | x | x | + | 18 | x | x | + | 9 2 | x | x |
| 192 | − | 96 | x | + | 12 | x | x | = | 2052 | − | 699 | x | + | 57 2 | x | x | + | 18 | x | x | + | 18 | x | x |