| x | = | 7800000 | − | 10 | × | 4 | × | 40 | × | 500 | ÷ | ( | ( | 40 | + | 10 | ) | × | 10 | × | 500 | ) |
| 方程两边同时乘以: | ( | ( | 40 | + | 10 | ) | × | 10 | × | 500 | ) |
| x | ( | ( | 40 | + | 10 | ) | × | 10 | × | 500 | ) | = | 7800000 | ( | ( | 40 | + | 10 | ) | × | 10 | × | 500 | ) | − | 10 | × | 4 | × | 40 | × | 500 |
| x | ( | 40 | + | 10 | ) | × | 10 | × | 500 | = | 7800000 | ( | ( | 40 | + | 10 | ) | × | 10 | × | 500 | ) | − | 10 | × | 4 | × | 40 | × | 500 |
| x | ( | 40 | + | 10 | ) | × | 10 | × | 500 | = | 7800000 | ( | 40 | + | 10 | ) | × | 10 | × | 500 | − | 10 | × | 4 | × | 40 | × | 500 |
| x= | 38999984 5 |