| 70 | ÷ | ( | 9 5 | − | X | ) | = | 130 | ÷ | ( | X | − | 8 5 | ) |
| 方程两边同时乘以: | ( | 9 5 | − | X | ) | , | ( | X | − | 8 5 | ) |
| 70 | ( | X | − | 8 5 | ) | = | 130 | ( | 9 5 | − | X | ) |
| 70 | X | − | 70 | × | 8 5 | = | 130 | ( | 9 5 | − | X | ) |
| 70 | X | − | 70 | × | 8 5 | = | 130 | × | 9 5 | − | 130 | X |
| 70 | X | − | 112 | = | 234 | − | 130 | X |
| 70 | X | + | 130 | X | = | 234 | + | 112 |
| 200 | X | = | 234 | + | 112 |
| 200 | X | = | 346 |
| X | = | 346 | ÷ | 200 |
| = | 346 | × | 1 200 |
| = | 173 | × | 1 100 |
| X | = | 173 100 |
| X | = | 1.73 |