| ( | 308 | − | ( | 96 | + | 65 | + | 25 | + | ( | x | − | 15 | − | 25 | ) | ) | ) | ÷ | 2 | = | x |
| 方程左边 = | 308 | × | 1 2 | − | ( | 96 | + | 65 | + | 25 | + | ( | x | − | 15 | − | 25 | ) | ) | × | 1 2 |
| = | 154 | − | ( | 96 | + | 65 | + | 25 | + | ( | x | − | 15 | − | 25 | ) | ) | × | 1 2 |
| = | 154 | − | 96 | × | 1 2 | − | 65 | × | 1 2 | − | 25 | × | 1 2 | − | ( | x | − | 15 | − | 25 | ) | × | 1 2 |
| = | 154 | − | 48 | − | 65 2 | − | 25 2 | − | ( | x | − | 15 | − | 25 | ) | × | 1 2 |
| = | 61 | − | ( | x | − | 15 | − | 25 | ) | × | 1 2 |
| = | 61 | − | x | × | 1 2 | + | 15 | × | 1 2 | + | 25 | × | 1 2 |
| = | 61 | − | x | × | 1 2 | + | 15 2 | + | 25 2 |
| = | 81 | − | 1 2 | x |
| 81 | − | 1 2 | x | = | x |
| - | 1 2 | x | − | x | = | - | 81 |
| - | 3 2 | x | = | - | 81 |
| 81 | = | 3 2 | x |
3 2 | x | = | 81 |
| x | = | 81 | ÷ | 3 2 |
| = | 81 | × | 2 3 |
| = | 27 | × | 2 |
| x | = | 54 |