| - | 4 | + | 1 | ÷ | 8 | × | a | = | 1 | ÷ | 2 | × | a | + | 2 | − | 3 | ÷ | 4 | × | a |
| 方程左边 = | - | 4 | + | 1 8 | a |
| - | 4 | + | 1 8 | a | = | 1 | ÷ | 2 | × | a | + | 2 | − | 3 | ÷ | 4 | × | a |
| 方程右边 = | 1 2 | a | + | 2 | − | 3 4 | a |
| = | - | 1 4 | a | + | 2 |
| - | 4 | + | 1 8 | a | = | - | 1 4 | a | + | 2 |
1 8 | a | + | 1 4 | a | = | 2 | + | 4 |
3 8 | a | = | 2 | + | 4 |
3 8 | a | = | 6 |
| a | = | 6 | ÷ | 3 8 |
| = | 6 | × | 8 3 |
| = | 2 | × | 8 |
| a | = | 16 |