| ( | 3500 | − | 3000 | ) | ( | 500 | − | x | ) | + | ( | 10000 | − | 8500 | ) | x | = | 450000 |
| Left side of the equation = | 3500 | ( | 500 | − | x | ) | − | 3000 | ( | 500 | − | x | ) | + | ( | 10000 | − | 8500 | ) | x |
| = | 3500 | × | 500 | − | 3500 | x | − | 3000 | ( | 500 | − | x | ) | + | ( | 10000 | − | 8500 | ) | x |
| = | 1750000 | − | 3500 | x | − | 3000 | ( | 500 | − | x | ) | + | ( | 10000 | − | 8500 | ) | x |
| = | 1750000 | − | 3500 | x | − | 3000 | × | 500 | + | 3000 | x | + | ( | 10000 | − | 8500 | ) | x |
| = | 1750000 | − | 3500 | x | − | 1500000 | + | 3000 | x | + | ( | 10000 | − | 8500 | ) | x |
| = | 250000 | − | 500 | x | + | ( | 10000 | − | 8500 | ) | x |
| = | 250000 | − | 500 | x | + | 10000 | x | − | 8500 | x |
| = | 250000 | + | 1000 | x |
| 250000 | + | 1000 | x | = | 450000 |
| 1000 | x | = | 450000 | − | 250000 |
| 1000 | x | = | 200000 |
| x | = | 200000 | ÷ | 1000 |
| = | 200000 | × | 1 1000 |
| = | 200 | × | 1 |
| x | = | 200 |