| ( | 558 | ÷ | 750 | ) | × | 750 | × | 3 5 | + | ( | X | ÷ | 300 | ) | × | 750 | × | 2 5 | = | 0 |
| Left side of the equation = | ( | 558 | ÷ | 750 | ) | × | 450 | + | ( | X | ÷ | 300 | ) | × | 300 |
| ( | 558 | ÷ | 750 | ) | × | 450 | + | ( | X | ÷ | 300 | ) | × | 300 | = | 0 |
| Left side of the equation = | 558 | ÷ | 750 | × | 450 | + | ( | X | ÷ | 300 | ) | × | 300 |
| = | 1674 5 | + | ( | X | ÷ | 300 | ) | × | 300 |
| = | 1674 5 | + | X | ÷ | 300 | × | 300 |
| = | 1674 5 | + | X | × | 1 |
1674 5 | + | 1 | X | = | 0 |
| 1 | X | = | 0 | − | 1674 5 |
| X | = | 0 | − | 1674 5 |
| X | = | - | 1674 5 |