| ( | 13750 | + | 250 | X | ) | ÷ | ( | 50 | + | X | ) | = | 250 |
| Multiply both sides of the equation by: | ( | 50 | + | X | ) |
| ( | 13750 | + | 250 | X | ) | = | 250 | ( | 50 | + | X | ) |
| 13750 | + | 250 | X | = | 250 | ( | 50 | + | X | ) |
| 13750 | + | 250 | X | = | 250 | × | 50 | + | 250 | X |
| 13750 | + | 250 | X | = | 12500 | + | 250 | X |
| 250 | X | − | 250 | X | = | 12500 | − | 13750 |
| 0 | X | = | 12500 | − | 13750 |
| 0 | X | = | - | 1250 |