| ( | 60 | − | 3 | x | ) | ( | 28 | − | x | ) | = | 32 |
| Left side of the equation = | 60 | ( | 28 | − | x | ) | − | 3 | x | ( | 28 | − | x | ) |
| = | 60 | × | 28 | − | 60 | x | − | 3 | x | ( | 28 | − | x | ) |
| = | 1680 | − | 60 | x | − | 3 | x | ( | 28 | − | x | ) |
| = | 1680 | − | 60 | x | − | 3 | x | × | 28 | + | 3 | x | x |
| = | 1680 | − | 60 | x | − | 84 | x | + | 3 | x | x |
| = | 1680 | − | 144 | x | + | 3 | x | x |
| 1680 | − | 144 | x | + | 3 | x | x | = | 32 |