| 4 | ( | h | − | 1 2 | ) | = | 7 |
| 方程左边 = | 4 | h | − | 4 | × | 1 2 |
| = | 4 | h | − | 2 |
| 4 | h | − | 2 | = | 7 |
| 4 | h | = | 7 | + | 2 |
| 4 | h | = | 9 |
| h | = | 9 | ÷ | 4 |
| = | 9 | × | 1 4 |
| h | = | 9 4 |
| h | = | 2.25 |
177 10 | = | 6 | V | − | 13 5 |
| - | 6 | V | = | - | 13 5 | − | 177 10 |
| - | 6 | V | = | - | 203 10 |
203 10 | = | 6 | V |
| 6 | V | = | 203 10 |
| V | = | 203 10 | ÷ | 6 |
| = | 203 10 | × | 1 6 |
| V | = | 203 60 |
| V | = | 3.383333 |
| 18 | = | n | ÷ | 4 | + | 2 |
| - | 1 4 | n | = | 2 | − | 18 |
| - | 1 4 | n | = | - | 16 |
| 16 | = | 1 4 | n |
1 4 | n | = | 16 |
| n | = | 16 | ÷ | 1 4 |
| = | 16 | × | 4 |
| n | = | 64 |