| X | = | 450 | ÷ | ( | 1 | + | ( | 1 | ÷ | 4 | ) | − | ( | 1 | ÷ | 2 | ) | − | ( | 3 | ÷ | 7 | ) | ) |
| 方程两边同时乘以: | ( | 1 | + | ( | 1 | ÷ | 4 | ) | − | ( | 1 | ÷ | 2 | ) | − | ( | 3 | ÷ | 7 | ) | ) |
| X | ( | 1 | + | ( | 1 | ÷ | 4 | ) | − | ( | 1 | ÷ | 2 | ) | − | ( | 3 | ÷ | 7 | ) | ) | = | 450 |
| X | × | 1 | + | X | ( | 1 | ÷ | 4 | ) | − | X | ( | 1 | ÷ | 2 | ) | − | X | ( | 3 | ÷ | 7 | ) | = | 450 |
| 1 | X | + | X | × | 1 | ÷ | 4 | − | X | ( | 1 | ÷ | 2 | ) | − | X | ( | 3 | ÷ | 7 | ) | = | 450 |
| 1 | X | + | X | × | 1 4 | − | X | ( | 1 | ÷ | 2 | ) | − | X | ( | 3 | ÷ | 7 | ) | = | 450 |
5 4 | X | − | X | ( | 1 | ÷ | 2 | ) | − | X | ( | 3 | ÷ | 7 | ) | = | 450 |
5 4 | X | − | X | × | 1 | ÷ | 2 | − | X | ( | 3 | ÷ | 7 | ) | = | 450 |
5 4 | X | − | X | × | 1 2 | − | X | ( | 3 | ÷ | 7 | ) | = | 450 |
3 4 | X | − | X | ( | 3 | ÷ | 7 | ) | = | 450 |
3 4 | X | − | X | × | 3 | ÷ | 7 | = | 450 |
3 4 | X | − | X | × | 3 7 | = | 450 |
9 28 | X | = | 450 |
| X | = | 450 | ÷ | 9 28 |
| = | 450 | × | 28 9 |
| = | 50 | × | 28 |
| X | = | 1400 |