| ( | 300 | − | X | ) | × | 1 | ÷ | 4 | + | 29 | = | 2 | ÷ | 5 | × | X |
| 方程左边 = | ( | 300 | − | X | ) | × | 1 4 | + | 29 |
| ( | 300 | − | X | ) | × | 1 4 | + | 29 | = | 2 | ÷ | 5 | × | X |
| 方程左边 = | 300 | × | 1 4 | − | X | × | 1 4 | + | 29 |
| = | 75 | − | X | × | 1 4 | + | 29 |
| = | 104 | − | 1 4 | X |
| 104 | − | 1 4 | X | = | 2 | ÷ | 5 | × | X |
| 方程右边 = | 2 5 | X |
| 104 | − | 1 4 | X | = | 2 5 | X |
| - | 1 4 | X | − | 2 5 | X | = | - | 104 |
| - | 13 20 | X | = | - | 104 |
| 104 | = | 13 20 | X |
13 20 | X | = | 104 |
| X | = | 104 | ÷ | 13 20 |
| = | 104 | × | 20 13 |
| = | 8 | × | 20 |
| X | = | 160 |