| 3 | x | ( | 3 | x | + | 1 | ) | ( | 3 | x | + | 2 | ) | = | 2021 |
| Left side of the equation = | 3 | x | × | 3 | x | ( | 3 | x | + | 2 | ) | + | 3 | x | × | 1 | ( | 3 | x | + | 2 | ) |
| = | 9 | x | x | ( | 3 | x | + | 2 | ) | + | 3 | x | ( | 3 | x | + | 2 | ) |
| = | 9 | x | x | × | 3 | x | + | 9 | x | x | × | 2 | + | 3 | x | ( | 3 | x | + | 2 | ) |
| = | 27 | x | x | x | + | 18 | x | x | + | 3 | x | ( | 3 | x | + | 2 | ) |
| = | 27 | x | x | x | + | 18 | x | x | + | 3 | x | × | 3 | x | + | 3 |
| = | 27 | x | x | x | + | 18 | x | x | + | 9 | x | x | + | 6 | x |
| 27 | x | x | x | + | 18 | x | x | + | 9 | x | x | + | 6 | x | = | 2021 |