| 125000 | − | ( | 400 | ( | 1 | − | a | ) | × | 200 | ( | 1 | + | a | ) | + | 150 | × | 3 4 | a | ) | = | 8750 |
| Left side of the equation = | 125000 | − | 400 | ( | 1 | − | a | ) | × | 200 | ( | 1 | + | a | ) | − | 150 | × | 3 4 | a |
| = | 125000 | − | 80000 | ( | 1 | − | a | ) | ( | 1 | + | a | ) | − | 225 2 | a |
| = | 125000 | − | 80000 | × | 1 | ( | 1 | + | a | ) | + | 80000 | a | ( | 1 | + | a | ) | − | 225 2 | a |
| = | 125000 | − | 80000 | ( | 1 | + | a | ) | + | 80000 | a | ( | 1 | + | a | ) | − | 225 2 | a |
| = | 125000 | − | 80000 | × | 1 | − | 80000 | a | + | 80000 | a | ( | 1 | + | a | ) | − | 225 2 | a |
| = | 125000 | − | 80000 | − | 80000 | a | + | 80000 | a | ( | 1 | + | a | ) | − | 225 2 | a |
| = | 45000 | − | 160225 2 | a | + | 80000 | a | ( | 1 | + | a | ) |
| = | 45000 | − | 160225 2 | a | + | 80000 | a | × | 1 | + | 80000 | a | a |
| = | 45000 | − | 160225 2 | a | + | 80000 | a | + | 80000 | a | a |
| = | 45000 | − | 225 2 | a | + | 80000 | a | a |
| 45000 | − | 225 2 | a | + | 80000 | a | a | = | 8750 |