| 50000 | ( | 1 | + | x | ) | × | 1 | ( | 1 | + | x | ÷ | 2 | ) | = | 66000 |
| Left side of the equation = | 50000 | ( | 1 | + | x | ) | ( | 1 | + | x | ÷ | 2 | ) |
| 50000 | ( | 1 | + | x | ) | ( | 1 | + | x | ÷ | 2 | ) | = | 66000 |
| Left side of the equation = | 50000 | × | 1 | ( | 1 | + | x | ÷ | 2 | ) | + | 50000 | x | ( | 1 | + | x | ÷ | 2 | ) |
| = | 50000 | ( | 1 | + | x | ÷ | 2 | ) | + | 50000 | x | ( | 1 | + | x | ÷ | 2 | ) |
| = | 50000 | × | 1 | + | 50000 | x | ÷ | 2 | + | 50000 | x | ( | 1 | + | x | ÷ | 2 | ) |
| = | 50000 | + | 25000 | x | + | 50000 | x | ( | 1 | + | x | ÷ | 2 | ) |
| = | 50000 | + | 25000 | x | + | 50000 | x | × | 1 | + | 50000 | x | x | ÷ | 2 |
| = | 50000 | + | 25000 | x | + | 50000 | x | + | 25000 | x | x |
| = | 50000 | + | 75000 | x | + | 25000 | x | x |
| 50000 | + | 75000 | x | + | 25000 | x | x | = | 66000 |
| x2= | 1 5 |