| ( | 4120 | + | 90 | x | ) | ÷ | ( | 97 2 | + | x | ) | = | 175 2 |
| 方程两边同时乘以: | ( | 97 2 | + | x | ) |
| ( | 4120 | + | 90 | x | ) | = | 175 2 | ( | 97 2 | + | x | ) |
| 4120 | + | 90 | x | = | 175 2 | ( | 97 2 | + | x | ) |
| 4120 | + | 90 | x | = | 175 2 | × | 97 2 | + | 175 2 | x |
| 4120 | + | 90 | x | = | 16975 4 | + | 175 2 | x |
| 90 | x | − | 175 2 | x | = | 16975 4 | − | 4120 |
5 2 | x | = | 16975 4 | − | 4120 |
5 2 | x | = | 495 4 |
| x | = | 495 4 | ÷ | 5 2 |
| = | 495 4 | × | 2 5 |
| = | 99 2 | × | 1 |
| x | = | 99 2 |
| x | = | 49.5 |