| ( | x | − | 180 | ) | × | 75 100 | ÷ | 1500 | = | ( | x | − | 180 | − | 4000 | × | 8 100 | ) | × | 75 100 | ÷ | 1000 |
| Left side of the equation = | ( | x | − | 180 | ) | × | 1 2000 |
| ( | x | − | 180 | ) | × | 1 2000 | = | ( | x | − | 180 | − | 4000 | × | 8 100 | ) | × | 75 100 | ÷ | 1000 |
| Left side of the equation = | x | × | 1 2000 | − | 180 | × | 1 2000 |
| = | x | × | 1 2000 | − | 9 100 |
1 2000 | x | − | 9 100 | = | ( | x | − | 180 | − | 4000 | × | 8 100 | ) | × | 75 100 | ÷ | 1000 |
| Right side of the equation = | ( | x | − | 180 | − | 4000 | × | 8 100 | ) | × | 3 4000 |
1 2000 | x | − | 9 100 | = | ( | x | − | 180 | − | 4000 | × | 8 100 | ) | × | 3 4000 |
| Right side of the equation = | x | × | 3 4000 | − | 180 | × | 3 4000 | − | 4000 | × | 8 100 | × | 3 4000 |
| = | x | × | 3 4000 | − | 27 200 | − | 6 25 |
| = | 3 4000 | x | − | 3 8 |
1 2000 | x | − | 9 100 | = | 3 4000 | x | − | 3 8 |
1 2000 | x | − | 3 4000 | x | = | - | 3 8 | + | 9 100 |
| - | 1 4000 | x | = | - | 3 8 | + | 9 100 |
| - | 1 4000 | x | = | - | 57 200 |
57 200 | = | 1 4000 | x |
1 4000 | x | = | 57 200 |
| x | = | 57 200 | ÷ | 1 4000 |
| = | 57 200 | × | 4000 |
| = | 57 | × | 20 |
| x | = | 1140 |