| ( | 1710 | + | x | ) | ÷ | ( | 1800 | + | x | ) | = | 75 100 |
| 方程两边同时乘以: | ( | 1800 | + | x | ) |
| ( | 1710 | + | x | ) | = | 75 100 | ( | 1800 | + | x | ) |
| 1710 | + | x | = | 75 100 | ( | 1800 | + | x | ) |
| 1710 | + | x | = | 75 100 | × | 1800 | + | 75 100 | x |
| 1710 | + | x | = | 1350 | + | 75 100 | x |
| x | − | 75 100 | x | = | 1350 | − | 1710 |
1 4 | x | = | 1350 | − | 1710 |
1 4 | x | = | - | 360 |
| x | = | - | 360 | ÷ | 1 4 |
| = | - | 360 | × | 4 |
| x | = | - | 1440 |