| ( | 8 100 | ( | 600 | − | x | ) | + | 40 100 | x | ) | ÷ | 600 | = | ( | 40 100 | ( | 400 | − | x | ) | + | 8 100 | x | ) | ÷ | 400 |
| Left side of the equation = | 8 100 | ( | 600 | − | x | ) | × | 1 600 | + | 40 100 | x | × | 1 600 |
| = | 1 7500 | ( | 600 | − | x | ) | + | 1 1500 | x |
| = | 1 7500 | × | 600 | − | 1 7500 | x | + | 1 1500 | x |
| = | 2 25 | − | 1 7500 | x | + | 1 1500 | x |
| = | 2 25 | + | 1 1875 | x |
2 25 | + | 1 1875 | x | = | ( | 40 100 | ( | 400 | − | x | ) | + | 8 100 | x | ) | ÷ | 400 |
| Right side of the equation = | 40 100 | ( | 400 | − | x | ) | × | 1 400 | + | 8 100 | x | × | 1 400 |
| = | 1 1000 | ( | 400 | − | x | ) | + | 1 5000 | x |
| = | 1 1000 | × | 400 | − | 1 1000 | x | + | 1 5000 | x |
| = | 2 5 | − | 1 1000 | x | + | 1 5000 | x |
| = | 2 5 | − | 1 1250 | x |
2 25 | + | 1 1875 | x | = | 2 5 | − | 1 1250 | x |
1 1875 | x | + | 1 1250 | x | = | 2 5 | − | 2 25 |
1 750 | x | = | 2 5 | − | 2 25 |
1 750 | x | = | 8 25 |
| x | = | 8 25 | ÷ | 1 750 |
| = | 8 25 | × | 750 |
| = | 8 | × | 30 |
| x | = | 240 |