90 100 | m | + | 10 100 | ( | 500 | − | m | ) | = | 40 100 | × | 500 |
| Left side of the equation = | 90 100 | m | + | 10 100 | × | 500 | − | 10 100 | m |
| = | 90 100 | m | + | 50 | − | 10 100 | m |
| = | 4 5 | m | + | 50 |
4 5 | m | + | 50 | = | 40 100 | × | 500 |
| Right side of the equation = | 200 |
4 5 | m | + | 50 | = | 200 |
4 5 | m | = | 200 | − | 50 |
4 5 | m | = | 150 |
| m | = | 150 | ÷ | 4 5 |
| = | 150 | × | 5 4 |
| = | 75 | × | 5 2 |
| m | = | 375 2 |
| m | = | 187.5 |