| ( | 75 100 | X | − | 645 | ) | ÷ | 3000 | = | ( | 75 100 | X | − | 375 | ) | ÷ | 4000 |
| Left side of the equation = | 75 100 | X | × | 1 3000 | − | 645 | × | 1 3000 |
| = | 1 4000 | X | − | 43 200 |
1 4000 | X | − | 43 200 | = | ( | 75 100 | X | − | 375 | ) | ÷ | 4000 |
| Right side of the equation = | 75 100 | X | × | 1 4000 | − | 375 | × | 1 4000 |
| = | 3 16000 | X | − | 3 32 |
1 4000 | X | − | 43 200 | = | 3 16000 | X | − | 3 32 |
1 4000 | X | − | 3 16000 | X | = | - | 3 32 | + | 43 200 |
1 16000 | X | = | - | 3 32 | + | 43 200 |
1 16000 | X | = | 97 800 |
| X | = | 97 800 | ÷ | 1 16000 |
| = | 97 800 | × | 16000 |
| = | 97 | × | 20 |
| X | = | 1940 |