| ( | X | − | 4 | ) | ÷ | ( | 5 | − | X | ) | = | 552 | ÷ | 660 |
| Multiply both sides of the equation by: | ( | 5 | − | X | ) |
| ( | X | − | 4 | ) | = | 552 | ÷ | 660 | × | ( | 5 | − | X | ) |
| X | − | 4 | = | 552 | ÷ | 660 | × | ( | 5 | − | X | ) |
| X | − | 4 | = | 552 | ÷ | 660 | × | 5 | − | 552 | ÷ | 660 | × | X |
| X | − | 4 | = | 46 11 | − | 46 55 | X |
| X | + | 46 55 | X | = | 46 11 | + | 4 |
101 55 | X | = | 46 11 | + | 4 |
101 55 | X | = | 90 11 |
| X | = | 90 11 | ÷ | 101 55 |
| = | 90 11 | × | 55 101 |
| = | 90 | × | 5 101 |
| X | = | 450 101 |
| X | = | 4.455446 |