3 2 | × | 30 | ÷ | x | + | 3 2 | = | 7 2 | × | 30 | ÷ | ( | 3 | + | x | ) | + | 7 2 | x | ÷ | ( | 3 | + | x | ) |
| 方程两边同时乘以: | x | , | ( | 3 | + | x | ) |
3 2 | × | 30 | ( | 3 | + | x | ) | + | 3 2 | x | ( | 3 | + | x | ) | = | 7 2 | × | 30 | x | + | 7 2 | x | x |
3 2 | × | 30 | × | 3 | + | 3 2 | × | 30 | x | + | 3 2 | x | ( | 3 | + | x | ) | = | 7 2 | × | 30 | x | + | 7 2 | x | x |
| 135 | + | 45 | x | + | 3 2 | x | ( | 3 | + | x | ) | = | 105 | x | + | 7 2 | x | x |
| 135 | + | 45 | x | + | 3 2 | x | × | 3 | + | 3 2 | x | x | = | 105 | x | + | 7 2 | x | x |
| 135 | + | 45 | x | + | 9 2 | x | + | 3 2 | x | x | = | 105 | x | + | 7 2 | x | x |
| 135 | + | 99 2 | x | + | 3 2 | x | x | = | 105 | x | + | 7 2 | x | x |
| x2= | 9 4 |