| X | ( | X | + | 5 | ) | ( | X | + | 10 | ) | ( | X | + | 15 | ) | = | 1056 |
| 方程左边 = | X | X | ( | X | + | 10 | ) | ( | X | + | 15 | ) | + | X | × | 5 | ( | X | + | 10 | ) | ( | X | + | 15 | ) |
| = | X | X | X | ( | X | + | 15 | ) | + | X | X | × | 10 | ( | X | + | 15 | ) | + | X | × | 5 | ( | X | + | 10 | ) | ( | X | + | 15 | ) |
| = | X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | ( | X | + | 15 | ) |
| = | X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | X |
| = | X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | X |
| = | X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | X |
| = | X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | X |
| = | X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | X |
| = | X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | X |
| = | X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | X |
| = | X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | X |
| X | X | X | X | + | X | X | X | × | 15 | + | X | X | × | 10 | X | = | 1056 |