| 450 | ( | 1 | + | x | ) | × | 2 | = | 600 |
| Left side of the equation = | 900 | ( | 1 | + | x | ) |
| 900 | ( | 1 | + | x | ) | = | 600 |
| Left side of the equation = | 900 | × | 1 | + | 900 | x |
| = | 900 | + | 900 | x |
| 900 | + | 900 | x | = | 600 |
| 900 | x | = | 600 | − | 900 |
| 900 | x | = | - | 300 |
| x | = | - | 300 | ÷ | 900 |
| = | - | 300 | × | 1 900 |
| = | - | 1 | × | 1 3 |
| x | = | - | 1 3 |
| x | = | - 0.333333 |