| 1000 | ( | a | ÷ | 2 | + | 1 | ) | × | 500 | ( | a | + | 1 | ) | = | 660000 |
| Left side of the equation = | 500000 | ( | a | ÷ | 2 | + | 1 | ) | ( | a | + | 1 | ) |
| 500000 | ( | a | ÷ | 2 | + | 1 | ) | ( | a | + | 1 | ) | = | 660000 |
| Left side of the equation = | 500000 | a | ÷ | 2 | × | ( | a | + | 1 | ) | + | 500000 | × | 1 | ( | a | + | 1 | ) |
| = | 250000 | a | ( | a | + | 1 | ) | + | 500000 | ( | a | + | 1 | ) |
| = | 250000 | a | a | + | 250000 | a | × | 1 | + | 500000 | ( | a | + | 1 | ) |
| = | 250000 | a | a | + | 250000 | a | + | 500000 | ( | a | + | 1 | ) |
| = | 250000 | a | a | + | 250000 | a | + | 500000 | a | + | 500000 | × | 1 |
| = | 250000 | a | a | + | 250000 | a | + | 500000 | a | + | 500000 |
| = | 250000 | a | a | + | 750000 | a | + | 500000 |
| 250000 | a | a | + | 750000 | a | + | 500000 | = | 660000 |
| a2= | 1 5 |