| ( | 12 | − | 1 2 | x | − | 6 | ) | ( | 30 | + | 5 | x | ) | = | 200 |
| Left side of the equation = | 12 | ( | 30 | + | 5 | x | ) | − | 1 2 | x | ( | 30 | + | 5 | x | ) | − | 6 | ( | 30 | + | 5 | x | ) |
| = | 12 | × | 30 | + | 12 | × | 5 | x | − | 1 2 | x | ( | 30 | + | 5 | x | ) | − | 6 | ( | 30 | + | 5 | x | ) |
| = | 360 | + | 60 | x | − | 1 2 | x | ( | 30 | + | 5 | x | ) | − | 6 | ( | 30 | + | 5 | x | ) |
| = | 360 | + | 60 | x | − | 1 2 | x | × | 30 | − | 1 2 | x | × | 5 | x | − | 6 | ( | 30 | + | 5 | x | ) |
| = | 360 | + | 60 | x | − | 15 | x | − | 5 2 | x | x | − | 6 | ( | 30 | + | 5 | x | ) |
| = | 360 | + | 45 | x | − | 5 2 | x | x | − | 6 | ( | 30 | + | 5 | x | ) |
| = | 360 | + | 45 | x | − | 5 2 | x | x | − | 6 | × | 30 | − | 6 | × | 5 | x |
| = | 360 | + | 45 | x | − | 5 2 | x | x | − | 180 | − | 30 | x |
| = | 180 | + | 15 | x | − | 5 2 | x | x |
| 180 | + | 15 | x | − | 5 2 | x | x | = | 200 |