| ( | x | − | 400 | × | 5 100 | − | 600 | × | 6 100 | ) | ( | 1 | − | 25 100 | ) | ÷ | 800 | = | ( | x | − | 400 | × | 5 100 | ) | ( | 1 | − | 25 100 | ) | ÷ | 820 |
| Left side of the equation = | x | ( | 1 | − | 25 100 | ) | × | 1 800 | − | 400 | × | 5 100 | ( | 1 | − | 25 100 | ) | × | 1 800 | − | 600 | × | 6 100 | ( | 1 | − | 25 100 | ) | × | 1 800 |
| = | x | ( | 1 | − | 25 100 | ) | × | 1 800 | − | 1 40 | ( | 1 | − | 25 100 | ) | − | 9 200 | ( | 1 | − | 25 100 | ) |
| = | x | × | 1 | × | 1 800 | − | x | × | 25 100 | × | 1 800 | − | 1 40 | ( | 1 | − | 25 100 | ) | − | 9 200 | ( | 1 | − | 25 100 | ) |
| = | x | × | 1 800 | − | x | × | 1 3200 | − | 1 40 | ( | 1 | − | 25 100 | ) | − | 9 200 | ( | 1 | − | 25 100 | ) |
| = | 3 3200 | x | − | 1 40 | ( | 1 | − | 25 100 | ) | − | 9 200 | ( | 1 | − | 25 100 | ) |
| = | 3 3200 | x | − | 1 40 | × | 1 | + | 1 40 | × | 25 100 | − | 9 200 | ( | 1 | − | 25 100 | ) |
| = | 3 3200 | x | − | 1 40 | + | 1 160 | − | 9 200 | ( | 1 | − | 25 100 | ) |
| = | 3 3200 | x | − | 3 160 | − | 9 200 | ( | 1 | − | 25 100 | ) |
| = | 3 3200 | x | − | 3 160 | − | 9 200 | × | 1 | + | 9 200 | × | 25 100 |
| = | 3 3200 | x | − | 3 160 | − | 9 200 | + | 9 800 |
| = | 3 3200 | x | − | 21 400 |
3 3200 | x | − | 21 400 | = | ( | x | − | 400 | × | 5 100 | ) | ( | 1 | − | 25 100 | ) | ÷ | 820 |
| Right side of the equation = | x | ( | 1 | − | 25 100 | ) | × | 1 820 | − | 400 | × | 5 100 | ( | 1 | − | 25 100 | ) | × | 1 820 |
| = | x | ( | 1 | − | 25 100 | ) | × | 1 820 | − | 1 41 | ( | 1 | − | 25 100 | ) |
| = | x | × | 1 | × | 1 820 | − | x | × | 25 100 | × | 1 820 | − | 1 41 | ( | 1 | − | 25 100 | ) |
| = | x | × | 1 820 | − | x | × | 1 3280 | − | 1 41 | ( | 1 | − | 25 100 | ) |
| = | 3 3280 | x | − | 1 41 | ( | 1 | − | 25 100 | ) |
| = | 3 3280 | x | − | 1 41 | × | 1 | + | 1 41 | × | 25 100 |
| = | 3 3280 | x | − | 1 41 | + | 1 164 |
| = | 3 3280 | x | − | 3 164 |
3 3200 | x | − | 21 400 | = | 3 3280 | x | − | 3 164 |
3 3200 | x | − | 3 3280 | x | = | - | 3 164 | + | 21 400 |
3 131200 | x | = | - | 3 164 | + | 21 400 |
3 131200 | x | = | 561 16400 |
| x | = | 561 16400 | ÷ | 3 131200 |
| = | 561 16400 | × | 131200 3 |
| = | 187 | × | 8 |
| x | = | 1496 |