| ( | 20 | + | 2 | X | ) | ( | 16 | + | 2 | X | ) | = | 480 |
| Left side of the equation = | 20 | ( | 16 | + | 2 | X | ) | + | 2 | X | ( | 16 | + | 2 | X | ) |
| = | 20 | × | 16 | + | 20 | × | 2 | X | + | 2 | X | ( | 16 | + | 2 | X | ) |
| = | 320 | + | 40 | X | + | 2 | X | ( | 16 | + | 2 | X | ) |
| = | 320 | + | 40 | X | + | 2 | X | × | 16 | + | 2 | X | × | 2 | X |
| = | 320 | + | 40 | X | + | 32 | X | + | 4 | X | X |
| = | 320 | + | 72 | X | + | 4 | X | X |
| 320 | + | 72 | X | + | 4 | X | X | = | 480 |