| 30000 | ( | 1 | + | ( | a | + | 5 | ) | ) | × | 1 100 | + | 2000 | × | 5 | a | ÷ | 6 100 | × | 15 | ( | 1 | + | a | ) | = | 21750 |
| Left side of the equation = | 300 | ( | 1 | + | ( | a | + | 5 | ) | ) | + | 2500000 | a | ( | 1 | + | a | ) |
| 300 | ( | 1 | + | ( | a | + | 5 | ) | ) | + | 2500000 | a | ( | 1 | + | a | ) | = | 21750 |
| Left side of the equation = | 300 | × | 1 | + | 300 | ( | a | + | 5 | ) | + | 2500000 | a | ( | 1 | + | a | ) |
| = | 300 | + | 300 | ( | a | + | 5 | ) | + | 2500000 | a | ( | 1 | + | a | ) |
| = | 300 | + | 300 | a | + | 300 | × | 5 | + | 2500000 | a | ( | 1 | + | a | ) |
| = | 300 | + | 300 | a | + | 1500 | + | 2500000 | a | ( | 1 | + | a | ) |
| = | 1800 | + | 300 | a | + | 2500000 | a | ( | 1 | + | a | ) |
| = | 1800 | + | 300 | a | + | 2500000 | a | × | 1 | + | 2500000 | a | a |
| = | 1800 | + | 300 | a | + | 2500000 | a | + | 2500000 | a | a |
| = | 1800 | + | 2500300 | a | + | 2500000 | a | a |
| 1800 | + | 2500300 | a | + | 2500000 | a | a | = | 21750 |