| ( | ( | ( | ( | X | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 2 | = | 999 |
| 方程左边 = | ( | ( | ( | X | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 2 | × | 2 | + | 6 | × | 2 |
| = | ( | ( | ( | X | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 4 | + | 12 |
| = | ( | ( | X | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 2 | × | 4 | + | 6 | × | 4 | + | 12 |
| = | ( | ( | X | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 8 | + | 24 | + | 12 |
| = | ( | ( | X | × | 2 | + | 6 | ) | × | 2 | + | 6 | ) | × | 8 | + | 36 |
| = | ( | X | × | 2 | + | 6 | ) | × | 2 | × | 8 | + | 6 | × | 8 | + | 36 |
| = | ( | X | × | 2 | + | 6 | ) | × | 16 | + | 48 | + | 36 |
| = | ( | X | × | 2 | + | 6 | ) | × | 16 | + | 84 |
| = | X | × | 2 | × | 16 | + | 6 | × | 16 | + | 84 |
| = | X | × | 32 | + | 96 | + | 84 |
| = | 32 | X | + | 180 |
| 32 | X | + | 180 | = | 999 |
| 32 | X | = | 999 | − | 180 |
| 32 | X | = | 819 |
| X | = | 819 | ÷ | 32 |
| = | 819 | × | 1 32 |
| X | = | 819 32 |
| X | = | 25.59375 |