| 500 | + | 500 | ( | 1 | + | x | ) | + | 500 | ( | 1 | + | x | ) | × | 2 | = | 1820 |
| Left side of the equation = | 500 | + | 500 | ( | 1 | + | x | ) | + | 1000 | ( | 1 | + | x | ) |
| 500 | + | 500 | ( | 1 | + | x | ) | + | 1000 | ( | 1 | + | x | ) | = | 1820 |
| Left side of the equation = | 500 | + | 500 | × | 1 | + | 500 | x | + | 1000 | ( | 1 | + | x | ) |
| = | 500 | + | 500 | + | 500 | x | + | 1000 | ( | 1 | + | x | ) |
| = | 1000 | + | 500 | x | + | 1000 | ( | 1 | + | x | ) |
| = | 1000 | + | 500 | x | + | 1000 | × | 1 | + | 1000 | x |
| = | 1000 | + | 500 | x | + | 1000 | + | 1000 | x |
| = | 2000 | + | 1500 | x |
| 2000 | + | 1500 | x | = | 1820 |
| 1500 | x | = | 1820 | − | 2000 |
| 1500 | x | = | - | 180 |
| x | = | - | 180 | ÷ | 1500 |
| = | - | 180 | × | 1 1500 |
| = | - | 3 | × | 1 25 |
| x | = | - | 3 25 |
| x | = | - 0.12 |