| ( | 3 4 | x | − | 405 2 | ) | ÷ | 9100 | = | ( | 3 4 | x | − | 270 | ) | ÷ | 9000 |
| 方程左边 = | 3 4 | x | × | 1 9100 | − | 405 2 | × | 1 9100 |
| = | 3 36400 | x | − | 81 3640 |
3 36400 | x | − | 81 3640 | = | ( | 3 4 | x | − | 270 | ) | ÷ | 9000 |
| 方程右边 = | 3 4 | x | × | 1 9000 | − | 270 | × | 1 9000 |
| = | 1 12000 | x | − | 3 100 |
3 36400 | x | − | 81 3640 | = | 1 12000 | x | − | 3 100 |
3 36400 | x | − | 1 12000 | x | = | - | 3 100 | + | 81 3640 |
| - | 1 1092000 | x | = | - | 3 100 | + | 81 3640 |
| - | 1 1092000 | x | = | - | 141 18200 |
141 18200 | = | 1 1092000 | x |
1 1092000 | x | = | 141 18200 |
| x | = | 141 18200 | ÷ | 1 1092000 |
| = | 141 18200 | × | 1092000 |
| = | 141 | × | 60 |
| x | = | 8460 |