| x | ÷ | ( | 7 200 | − | x | ) | ÷ | ( | 27 1000 | − | x | ) | = | 150000000 |
| 方程两边同时乘以: | ( | 7 200 | − | x | ) |
| x | ÷ | ( | 27 1000 | − | x | ) | = | 150000000 | ( | 7 200 | − | x | ) |
| x | ÷ | ( | 27 1000 | − | x | ) | = | 150000000 | × | 7 200 | − | 150000000 | x |
| x | ÷ | ( | 27 1000 | − | x | ) | = | 5250000 | − | 150000000 | x |
| 方程两边同时乘以: | ( | 27 1000 | − | x | ) |
| x | = | 5250000 | ( | 27 1000 | − | x | ) | − | 150000000 | x | ( | 27 1000 | − | x | ) |
| x | = | 5250000 | × | 27 1000 | − | 5250000 | x | − | 150000000 | x | ( | 27 1000 | − | x | ) |
| x | = | 141750 | − | 5250000 | x | − | 150000000 | x | ( | 27 1000 | − | x | ) |
| x | = | 141750 | − | 5250000 | x | − | 150000000 | x | × | 27 1000 | + | 150000000 | x | x |
| x | = | 141750 | − | 5250000 | x | − | 4050000 | x | + | 150000000 | x | x |
| x | = | 141750 | − | 9300000 | x | + | 150000000 | x | x |