| 300 | ( | 1 | + | x | ) | × | 2 | = | 432 |
| Left side of the equation = | 600 | ( | 1 | + | x | ) |
| 600 | ( | 1 | + | x | ) | = | 432 |
| Left side of the equation = | 600 | × | 1 | + | 600 | x |
| = | 600 | + | 600 | x |
| 600 | + | 600 | x | = | 432 |
| 600 | x | = | 432 | − | 600 |
| 600 | x | = | - | 168 |
| x | = | - | 168 | ÷ | 600 |
| = | - | 168 | × | 1 600 |
| = | - | 7 | × | 1 25 |
| x | = | - | 7 25 |
| x | = | - 0.28 |