| ( | X | − | 180 | ) | ( | 1 | − | 3 4 | ) | ÷ | 2400 | = | ( | X | − | 450 | ) | ( | 1 | − | 3 4 | ) | ÷ | 2000 |
| Left side of the equation = | X | ( | 1 | − | 3 4 | ) | × | 1 2400 | − | 180 | ( | 1 | − | 3 4 | ) | × | 1 2400 |
| = | X | ( | 1 | − | 3 4 | ) | × | 1 2400 | − | 3 40 | ( | 1 | − | 3 4 | ) |
| = | X | × | 1 | × | 1 2400 | − | X | × | 3 4 | × | 1 2400 | − | 3 40 | ( | 1 | − | 3 4 | ) |
| = | X | × | 1 2400 | − | X | × | 1 3200 | − | 3 40 | ( | 1 | − | 3 4 | ) |
| = | 1 9600 | X | − | 3 40 | ( | 1 | − | 3 4 | ) |
| = | 1 9600 | X | − | 3 40 | × | 1 | + | 3 40 | × | 3 4 |
| = | 1 9600 | X | − | 3 40 | + | 9 160 |
| = | 1 9600 | X | − | 3 160 |
1 9600 | X | − | 3 160 | = | ( | X | − | 450 | ) | ( | 1 | − | 3 4 | ) | ÷ | 2000 |
| Right side of the equation = | X | ( | 1 | − | 3 4 | ) | × | 1 2000 | − | 450 | ( | 1 | − | 3 4 | ) | × | 1 2000 |
| = | X | ( | 1 | − | 3 4 | ) | × | 1 2000 | − | 9 40 | ( | 1 | − | 3 4 | ) |
| = | X | × | 1 | × | 1 2000 | − | X | × | 3 4 | × | 1 2000 | − | 9 40 | ( | 1 | − | 3 4 | ) |
| = | X | × | 1 2000 | − | X | × | 3 8000 | − | 9 40 | ( | 1 | − | 3 4 | ) |
| = | 1 8000 | X | − | 9 40 | ( | 1 | − | 3 4 | ) |
| = | 1 8000 | X | − | 9 40 | × | 1 | + | 9 40 | × | 3 4 |
| = | 1 8000 | X | − | 9 40 | + | 27 160 |
| = | 1 8000 | X | − | 9 160 |
1 9600 | X | − | 3 160 | = | 1 8000 | X | − | 9 160 |
1 9600 | X | − | 1 8000 | X | = | - | 9 160 | + | 3 160 |
| - | 1 48000 | X | = | - | 9 160 | + | 3 160 |
| - | 1 48000 | X | = | - | 3 80 |
3 80 | = | 1 48000 | X |
1 48000 | X | = | 3 80 |
| X | = | 3 80 | ÷ | 1 48000 |
| = | 3 80 | × | 48000 |
| = | 3 | × | 600 |
| X | = | 1800 |