| ( | 150 | x | − | 7200000 | ) | ÷ | 7200000 | × | 100 | = | 5 100 |
| 方程左边 = | ( | 150 | x | − | 7200000 | ) | × | 1 72000 |
| ( | 150 | x | − | 7200000 | ) | × | 1 72000 | = | 5 100 |
| 方程左边 = | 150 | x | × | 1 72000 | − | 7200000 | × | 1 72000 |
| = | 1 480 | x | − | 100 |
1 480 | x | − | 100 | = | 5 100 |
1 480 | x | = | 5 100 | + | 100 |
1 480 | x | = | 2001 20 |
| x | = | 2001 20 | ÷ | 1 480 |
| = | 2001 20 | × | 480 |
| = | 2001 | × | 24 |
| x | = | 48024 |