| ( | X | − | 180 | ) | × | 3 4 | ÷ | 2400 | = | ( | ( | X | − | 180 | ) | × | 3 4 | − | 300 | ) | ÷ | 2000 |
| Left side of the equation = | ( | X | − | 180 | ) | × | 1 3200 |
| ( | X | − | 180 | ) | × | 1 3200 | = | ( | ( | X | − | 180 | ) | × | 3 4 | − | 300 | ) | ÷ | 2000 |
| Left side of the equation = | X | × | 1 3200 | − | 180 | × | 1 3200 |
| = | X | × | 1 3200 | − | 9 160 |
1 3200 | X | − | 9 160 | = | ( | ( | X | − | 180 | ) | × | 3 4 | − | 300 | ) | ÷ | 2000 |
| Right side of the equation = | ( | X | − | 180 | ) | × | 3 4 | × | 1 2000 | − | 300 | × | 1 2000 |
| = | ( | X | − | 180 | ) | × | 3 8000 | − | 3 20 |
| = | X | × | 3 8000 | − | 180 | × | 3 8000 | − | 3 20 |
| = | X | × | 3 8000 | − | 27 400 | − | 3 20 |
| = | 3 8000 | X | − | 87 400 |
1 3200 | X | − | 9 160 | = | 3 8000 | X | − | 87 400 |
1 3200 | X | − | 3 8000 | X | = | - | 87 400 | + | 9 160 |
| - | 1 16000 | X | = | - | 87 400 | + | 9 160 |
| - | 1 16000 | X | = | - | 129 800 |
129 800 | = | 1 16000 | X |
1 16000 | X | = | 129 800 |
| X | = | 129 800 | ÷ | 1 16000 |
| = | 129 800 | × | 16000 |
| = | 129 | × | 20 |
| X | = | 2580 |