| ( | 6 | − | x | ) | ( | 200 | − | 5 | x | ) | − | 2 | ( | 200 | − | 50 | x | ) | = | 1250 |
| Left side of the equation = | 6 | ( | 200 | − | 5 | x | ) | − | x | ( | 200 | − | 5 | x | ) | − | 2 | ( | 200 | − | 50 | x | ) |
| = | 6 | × | 200 | − | 6 | × | 5 | x | − | x | ( | 200 | − | 5 | x | ) | − | 2 | ( | 200 | − | 50 | x | ) |
| = | 1200 | − | 30 | x | − | x | ( | 200 | − | 5 | x | ) | − | 2 | ( | 200 | − | 50 | x | ) |
| = | 1200 | − | 30 | x | − | x | × | 200 | + | x | × | 5 | x | − | 2 | ( | 200 | − | 50 | x | ) |
| = | 1200 | − | 230 | x | + | x | × | 5 | x | − | 2 | ( | 200 | − | 50 | x | ) |
| = | 1200 | − | 230 | x | + | x | × | 5 | x | − | 2 | × | 200 | + | 2 | × | 50 | x |
| = | 1200 | − | 230 | x | + | x | × | 5 | x | − | 400 | + | 100 | x |
| = | 800 | − | 130 | x | + | x | × | 5 | x |
| 800 | − | 130 | x | + | x | × | 5 | x | = | 1250 |