| 450 | × | 2 | ÷ | 9 | + | X | = | ( | 450 | + | X | ) | × | 2 | ÷ | 7 |
| Left side of the equation = | 100 | + | X |
| 100 | + | X | = | ( | 450 | + | X | ) | × | 2 | ÷ | 7 |
| Right side of the equation = | ( | 450 | + | X | ) | × | 2 7 |
| 100 | + | X | = | ( | 450 | + | X | ) | × | 2 7 |
| Right side of the equation = | 450 | × | 2 7 | + | X | × | 2 7 |
| = | 900 7 | + | X | × | 2 7 |
| 100 | + | X | = | 900 7 | + | 2 7 | X |
| X | − | 2 7 | X | = | 900 7 | − | 100 |
5 7 | X | = | 900 7 | − | 100 |
5 7 | X | = | 200 7 |
| X | = | 200 7 | ÷ | 5 7 |
| = | 200 7 | × | 7 5 |
| = | 40 | × | 1 |
| X | = | 40 |