| ( | 98 | + | X | ) | ÷ | ( | 105 | + | X | ) | = | 49 50 |
| Multiply both sides of the equation by: | ( | 105 | + | X | ) |
| ( | 98 | + | X | ) | = | 49 50 | ( | 105 | + | X | ) |
| 98 | + | X | = | 49 50 | ( | 105 | + | X | ) |
| 98 | + | X | = | 49 50 | × | 105 | + | 49 50 | X |
| 98 | + | X | = | 1029 10 | + | 49 50 | X |
| X | − | 49 50 | X | = | 1029 10 | − | 98 |
1 50 | X | = | 1029 10 | − | 98 |
1 50 | X | = | 49 10 |
| X | = | 49 10 | ÷ | 1 50 |
| = | 49 10 | × | 50 |
| = | 49 | × | 5 |
| X | = | 245 |