| ( | 168 | + | x | ) | ÷ | ( | 48 | + | 220 | − | x | ) | = | 17 8 |
| 方程两边同时乘以: | ( | 48 | + | 220 | − | x | ) |
| ( | 168 | + | x | ) | = | 17 8 | ( | 48 | + | 220 | − | x | ) |
| 168 | + | x | = | 17 8 | ( | 48 | + | 220 | − | x | ) |
| 168 | + | x | = | 17 8 | × | 48 | + | 17 8 | × | 220 | − | 17 8 | x |
| 168 | + | x | = | 102 | + | 935 2 | − | 17 8 | x |
| 168 | + | x | = | 1139 2 | − | 17 8 | x |
| x | + | 17 8 | x | = | 1139 2 | − | 168 |
25 8 | x | = | 1139 2 | − | 168 |
25 8 | x | = | 803 2 |
| x | = | 803 2 | ÷ | 25 8 |
| = | 803 2 | × | 8 25 |
| = | 803 | × | 4 25 |
| x | = | 3212 25 |
| x | = | 128.48 |