| 7 | ÷ | ( | x | + | 2 | ) | × | ( | x | + | 9 | ) | = | 5 | ÷ | ( | x | + | 3 | ) | × | ( | x | + | 8 | ) |
| 方程两边同时乘以: | ( | x | + | 2 | ) | , | ( | x | + | 3 | ) |
| 7 | ( | x | + | 9 | ) | ( | x | + | 3 | ) | = | 5 | ( | x | + | 8 | ) | ( | x | + | 2 | ) |
| 7 | x | ( | x | + | 3 | ) | + | 7 | × | 9 | ( | x | + | 3 | ) | = | 5 | ( | x | + | 8 | ) | ( | x | + | 2 | ) |
| 7 | x | ( | x | + | 3 | ) | + | 7 | × | 9 | ( | x | + | 3 | ) | = | 5 | x | ( | x | + | 2 | ) | + | 5 | × | 8 | ( | x | + | 2 | ) |
| 7 | x | ( | x | + | 3 | ) | + | 63 | ( | x | + | 3 | ) | = | 5 | x | ( | x | + | 2 | ) | + | 40 | ( | x | + | 2 | ) |
| 7 | x | x | + | 7 | x | × | 3 | + | 63 | ( | x | + | 3 | ) | = | 5 | x | ( | x | + | 2 | ) | + | 40 | ( | x | + | 2 | ) |
| 7 | x | x | + | 7 | x | × | 3 | + | 63 | ( | x | + | 3 | ) | = | 5 | x | x | + | 5 | x | × | 2 | + | 40 | ( | x | + | 2 | ) |
| 7 | x | x | + | 21 | x | + | 63 | ( | x | + | 3 | ) | = | 5 | x | x | + | 10 | x | + | 40 | ( | x | + | 2 | ) |
| 7 | x | x | + | 21 | x | + | 63 | x | + | 63 | × | 3 | = | 5 | x | x | + | 10 | x | + | 40 | ( | x | + | 2 | ) |
| 7 | x | x | + | 21 | x | + | 63 | x | + | 63 | × | 3 | = | 5 | x | x | + | 10 | x | + | 40 | x | + | 40 | × | 2 |
| 7 | x | x | + | 21 | x | + | 63 | x | + | 189 | = | 5 | x | x | + | 10 | x | + | 40 | x | + | 80 |
| 7 | x | x | + | 84 | x | + | 189 | = | 5 | x | x | + | 50 | x | + | 80 |