| ( | 6 | X | − | 50 | ) | ÷ | ( | 5 | X | − | 50 | ) | = | 7 | ÷ | 5 |
| Multiply both sides of the equation by: | ( | 5 | X | − | 50 | ) |
| ( | 6 | X | − | 50 | ) | = | 7 | ÷ | 5 | × | ( | 5 | X | − | 50 | ) |
| 6 | X | − | 50 | = | 7 | ÷ | 5 | × | ( | 5 | X | − | 50 | ) |
| 6 | X | − | 50 | = | 7 | ÷ | 5 | × | 5 | X | − | 7 | ÷ | 5 | × | 50 |
| 6 | X | − | 50 | = | 7 | X | − | 70 |
| 6 | X | − | 7 | X | = | - | 70 | + | 50 |
| - | X | = | - | 70 | + | 50 |
| - | X | = | - | 70 | + | 50 |
| - | X | = | - | 20 |
| 20 | = | X |
| X | = | 20 |