| ( | 30 | × | 1 10 | + | x | ) | ÷ | ( | 30 | + | x | ) | = | 1 4 |
| 方程两边同时乘以: | ( | 30 | + | x | ) |
| ( | 30 | × | 1 10 | + | x | ) | = | 1 4 | ( | 30 | + | x | ) |
| 30 | × | 1 10 | + | x | = | 1 4 | ( | 30 | + | x | ) |
| 30 | × | 1 10 | + | x | = | 1 4 | × | 30 | + | 1 4 | x |
| 3 | + | x | = | 15 2 | + | 1 4 | x |
| x | − | 1 4 | x | = | 15 2 | − | 3 |
3 4 | x | = | 15 2 | − | 3 |
3 4 | x | = | 9 2 |
| x | = | 9 2 | ÷ | 3 4 |
| = | 9 2 | × | 4 3 |
| = | 3 | × | 2 |
| x | = | 6 |