| ( | 8 | + | 2 | x | ) | ( | 20 | + | 2 | x | ) | − | 160 | = | 60 |
| Left side of the equation = | 8 | ( | 20 | + | 2 | x | ) | + | 2 | x | ( | 20 | + | 2 | x | ) | − | 160 |
| = | 8 | × | 20 | + | 8 | × | 2 | x | + | 2 | x | ( | 20 | + | 2 | x | ) | − | 160 |
| = | 160 | + | 16 | x | + | 2 | x | ( | 20 | + | 2 | x | ) | − | 160 |
| = | 0 | + | 16 | x | + | 2 | x | ( | 20 | + | 2 | x | ) |
| = | 0 | + | 16 | x | + | 2 | x | × | 20 | + | 2 | x | × | 2 | x |
| = | 0 | + | 16 | x | + | 40 | x | + | 4 | x | x |
| = | 0 | + | 56 | x | + | 4 | x | x |
| 0 | + | 56 | x | + | 4 | x | x | = | 60 |