| ( | X | − | 40 | ) | ÷ | 10 | = | ( | X | − | 24 | ) | ÷ | 14 |
| 方程左边 = | X | × | 1 10 | − | 40 | × | 1 10 |
| = | X | × | 1 10 | − | 4 |
1 10 | X | − | 4 | = | ( | X | − | 24 | ) | ÷ | 14 |
| 方程右边 = | X | × | 1 14 | − | 24 | × | 1 14 |
| = | X | × | 1 14 | − | 12 7 |
1 10 | X | − | 4 | = | 1 14 | X | − | 12 7 |
1 10 | X | − | 1 14 | X | = | - | 12 7 | + | 4 |
1 35 | X | = | - | 12 7 | + | 4 |
1 35 | X | = | 16 7 |
| X | = | 16 7 | ÷ | 1 35 |
| = | 16 7 | × | 35 |
| = | 16 | × | 5 |
| X | = | 80 |