| ( | 8 | + | 9 | + | 9 | + | 8 | + | x | ) | ÷ | ( | 7 | + | 8 | + | 8 | + | 9 | + | x | ) | = | 3 | ÷ | 2 |
| 方程两边同时乘以: | ( | 7 | + | 8 | + | 8 | + | 9 | + | x | ) |
| ( | 8 | + | 9 | + | 9 | + | 8 | + | x | ) | = | 3 | ÷ | 2 | × | ( | 7 | + | 8 | + | 8 | + | 9 | + | x | ) |
| 8 | + | 9 | + | 9 | + | 8 | + | x | = | 3 | ÷ | 2 | × | ( | 7 | + | 8 | + | 8 | + | 9 | + | x | ) |
| 8 | + | 9 | + | 9 | + | 8 | + | x | = | 3 | ÷ | 2 | × | 7 | + | 3 | ÷ | 2 | × | 8 | + | 3 | ÷ | 2 | × | 8 | + | 3 | ÷ | 2 | × | 9 |
| 8 | + | 9 | + | 9 | + | 8 | + | x | = | 21 2 | + | 12 | + | 12 | + | 27 2 | + | 3 2 | x |
| 34 | + | x | = | 48 | + | 3 2 | x |
| x | − | 3 2 | x | = | 48 | − | 34 |
| - | 1 2 | x | = | 48 | − | 34 |
| - | 1 2 | x | = | 14 |
| - | 14 | = | 1 2 | x |
1 2 | x | = | - | 14 |
| x | = | - | 14 | ÷ | 1 2 |
| = | - | 14 | × | 2 |
| x | = | - | 28 |