30 100 | = | ( | x | − | 879 | ) | ÷ | x | × | 100 100 |
| 方程两边同时乘以: | x |
30 100 | x | = | ( | x | − | 879 | ) | × | 100 100 |
30 100 | x | = | x | × | 100 100 | − | 879 | × | 100 100 |
30 100 | x | = | x | × | 100 100 | − | 879 |
30 100 | x | − | 100 100 | x | = | - | 879 |
| - | 7 10 | x | = | - | 879 |
| 879 | = | 7 10 | x |
7 10 | x | = | 879 |
| x | = | 879 | ÷ | 7 10 |
| = | 879 | × | 10 7 |
| x | = | 8790 7 |
| x | = | 1255.714286 |