1 2 | × | 14 | ( | 6 | + | 3 | ÷ | 2 | × | n | ) | = | 72 | − | 1 2 | × | 14 | ( | 6 | + | 3 | ÷ | 2 | × | n | ) | − | 1 | ÷ | 2 | × | ( | - | n | ) | ( | 6 | − | 3 | ÷ | 2 | × | n | ) | × | 1 | ÷ | 2 | × | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| 方程左边 = | 7 | ( | 6 | + | 3 | ÷ | 2 | × | n | ) |
| 7 | ( | 6 | + | 3 | ÷ | 2 | × | n | ) | = | 72 | − | 1 2 | × | 14 | ( | 6 | + | 3 | ÷ | 2 | × | n | ) | − | 1 | ÷ | 2 | × | ( | - | n | ) | ( | 6 | − | 3 | ÷ | 2 | × | n | ) | × | 1 | ÷ | 2 | × | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| 方程左边 = | 7 | × | 6 | + | 7 | × | 3 | ÷ | 2 | × | n |
| = | 42 | + | 21 2 | n |
| 42 | + | 21 2 | n | = | 72 | − | 1 2 | × | 14 | ( | 6 | + | 3 | ÷ | 2 | × | n | ) | − | 1 | ÷ | 2 | × | ( | - | n | ) | ( | 6 | − | 3 | ÷ | 2 | × | n | ) | × | 1 | ÷ | 2 | × | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| 方程右边 = | 72 | − | 7 | ( | 6 | + | 3 | ÷ | 2 | × | n | ) | − | 1 4 | ( | - | n | ) | ( | 6 | − | 3 | ÷ | 2 | × | n | ) | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| 42 | + | 21 2 | n | = | 72 | − | 7 | ( | 6 | + | 3 | ÷ | 2 | × | n | ) | − | 1 4 | ( | - | n | ) | ( | 6 | − | 3 | ÷ | 2 | × | n | ) | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| 方程右边 = | 72 | − | 7 | × | 6 | − | 7 | × | 3 | ÷ | 2 | × | n | − | 1 4 | ( | - | n | ) | ( | 6 | − | 3 | ÷ | 2 | × | n | ) | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| = | 72 | − | 42 | − | 21 2 | n | − | 1 4 | ( | - | n | ) | ( | 6 | − | 3 | ÷ | 2 | × | n | ) | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| = | 30 | − | 21 2 | n | − | 1 4 | ( | - | n | ) | ( | 6 | − | 3 | ÷ | 2 | × | n | ) | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| = | 30 | − | 21 2 | n | + | 1 4 | n | ( | 6 | − | 3 | ÷ | 2 | × | n | ) | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| = | 30 | − | 21 2 | n | + | 1 4 | n | × | 6 | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) | − | 1 4 | n | × | 3 | ÷ | 2 |
| = | 30 | − | 21 2 | n | + | 3 2 | n | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) | − | 3 8 | n | n | ( | 10 | + | n | ) | ( | - | 3 | ÷ | 2 | × | n | ) |
| = | 30 | − | 21 2 | n | + | 3 2 | n | × | 10 | ( | - | 3 | ÷ | 2 | × | n | ) | + | 3 2 | n | n | ( | - | 3 | ÷ | 2 | × | n | ) | − | 3 8 |
| = | 30 | − | 21 2 | n | + | 15 | n | ( | - | 3 | ÷ | 2 | × | n | ) | + | 3 2 | n | n | ( | - | 3 | ÷ | 2 | × | n | ) | − | 3 8 | n |
| = | 30 | − | 21 2 | n | − | 15 | n | × | 3 | ÷ | 2 | × | n | + | 3 2 | n | n | ( | - | 3 | ÷ | 2 | × | n | ) |
| = | 30 | − | 21 2 | n | − | 45 2 | n | n | + | 3 2 | n | n | ( | - | 3 | ÷ | 2 | × | n | ) | − | 3 8 | n |
| = | 30 | − | 21 2 | n | − | 45 2 | n | n | − | 3 2 | n | n | × | 3 | ÷ | 2 | × | n |
| = | 30 | − | 21 2 | n | − | 45 2 | n | n | − | 9 4 | n | n | n | − | 3 8 | n |
| = | 30 | − | 21 2 | n | − | 45 2 | n | n | − | 9 4 | n | n | n | − | 3 8 | n |
| = | 30 | − | 21 2 | n | − | 45 2 | n | n | − | 9 4 | n | n | n | − | 15 4 | n |
| = | 30 | − | 21 2 | n | − | 45 2 | n | n | − | 9 4 | n | n | n | + | 15 4 | n |
| = | 30 | − | 21 2 | n | − | 45 2 | n | n | − | 9 4 | n | n | n | + | 45 8 | n |
| = | 30 | − | 21 2 | n | − | 45 2 | n | n | − | 9 4 | n | n | n | + | 45 8 | n |
| = | 30 | − | 21 2 | n | − | 45 2 | n | n | − | 9 4 | n | n | n | + | 45 8 | n |