| 200 | ( | 80 | − | 50 | ) | + | ( | 80 | − | x | − | 50 | ) | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) | = | 9000 |
| Left side of the equation = | 200 | × | 80 | − | 200 | × | 50 | + | ( | 80 | − | x | − | 50 | ) | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 16000 | − | 10000 | + | ( | 80 | − | x | − | 50 | ) | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 6000 | + | ( | 80 | − | x | − | 50 | ) | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 6000 | + | 80 | ( | 200 | + | 10 | x | ) | − | x | ( | 200 | + | 10 | x | ) | − | 50 | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 6000 | + | 80 | × | 200 | + | 80 | × | 10 | x | − | x | ( | 200 | + | 10 | x | ) | − | 50 | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 6000 | + | 16000 | + | 800 | x | − | x | ( | 200 | + | 10 | x | ) | − | 50 | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 22000 | + | 800 | x | − | x | ( | 200 | + | 10 | x | ) | − | 50 | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 22000 | + | 800 | x | − | x | × | 200 | − | x | × | 10 | x | − | 50 | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 22000 | + | 600 | x | − | x | × | 10 | x | − | 50 | ( | 200 | + | 10 | x | ) | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 22000 | + | 600 | x | − | x | × | 10 | x | − | 50 | × | 200 | − | 50 | × | 10 | x | + | ( | 40 | − | 50 | ) |
| = | 22000 | + | 600 | x | − | x | × | 10 | x | − | 10000 | − | 500 | x | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 12000 | + | 100 | x | − | x | × | 10 | x | + | ( | 40 | − | 50 | ) | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 12000 | + | 100 | x | − | x | × | 10 | x | + | 40 | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) | − | 50 | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 12000 | + | 100 | x | − | x | × | 10 | x | + | 40 | × | 800 | − | 40 | × | 200 | − | 40 | ( | 200 | + | 10 | x | ) |
| = | 12000 | + | 100 | x | − | x | × | 10 | x | + | 32000 | − | 8000 | − | 40 | ( | 200 | + | 10 | x | ) | − | 50 | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 36000 | + | 100 | x | − | x | × | 10 | x | − | 40 | ( | 200 | + | 10 | x | ) | − | 50 | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 36000 | + | 100 | x | − | x | × | 10 | x | − | 40 | × | 200 | − | 40 | × | 10 | x | − | 50 |
| = | 36000 | + | 100 | x | − | x | × | 10 | x | − | 8000 | − | 400 | x | − | 50 | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 28000 | − | 300 | x | − | x | × | 10 | x | − | 50 | ( | 800 | − | 200 | − | ( | 200 | + | 10 | x | ) | ) |
| = | 28000 | − | 300 | x | − | x | × | 10 | x | − | 50 | × | 800 | + | 50 | × | 200 | + | 50 | ( | 200 | + | 10 | x | ) |
| = | 28000 | − | 300 | x | − | x | × | 10 | x | − | 40000 | + | 10000 | + | 50 | ( | 200 | + | 10 | x | ) |
| = | - | 2000 | − | 300 | x | − | x | × | 10 | x | + | 50 | ( | 200 | + | 10 | x | ) |
| = | - | 2000 | − | 300 | x | − | x | × | 10 | x | + | 50 | × | 200 | + | 50 | × | 10 | x |
| = | - | 2000 | − | 300 | x | − | x | × | 10 | x | + | 10000 | + | 500 | x |
| = | 8000 | + | 200 | x | − | x | × | 10 | x |