| 400 | ( | 1 | + | a | ÷ | 100 | ) | × | 24 | + | 500 | × | 24 | ( | 1 | + | 2 | a | ÷ | 100 | ) | ( | 1 | + | a | ÷ | 100 | ) | = | 21600 | ( | 1 | + | 20 | ÷ | 9 | × | a | ÷ | 100 | ) |
| Left side of the equation = | 9600 | ( | 1 | + | a | ÷ | 100 | ) | + | 12000 | ( | 1 | + | 2 | a | ÷ | 100 | ) | ( | 1 | + | a | ÷ | 100 | ) |
| 9600 | ( | 1 | + | a | ÷ | 100 | ) | + | 12000 | ( | 1 | + | 2 | a | ÷ | 100 | ) | ( | 1 | + | a | ÷ | 100 | ) | = | 21600 | ( | 1 | + | 20 | ÷ | 9 | × | a | ÷ | 100 | ) |
| Left side of the equation = | 9600 | × | 1 | + | 9600 | a | ÷ | 100 | + | 12000 | ( | 1 | + | 2 | a | ÷ | 100 | ) | ( | 1 | + | a | ÷ | 100 | ) |
| = | 9600 | + | 96 | a | + | 12000 | ( | 1 | + | 2 | a | ÷ | 100 | ) | ( | 1 | + | a | ÷ | 100 | ) |
| = | 9600 | + | 96 | a | + | 12000 | × | 1 | ( | 1 | + | a | ÷ | 100 | ) | + | 12000 | × | 2 | a | ÷ | 100 | × | ( | 1 | + | a | ÷ | 100 | ) |
| = | 9600 | + | 96 | a | + | 12000 | ( | 1 | + | a | ÷ | 100 | ) | + | 240 | a | ( | 1 | + | a | ÷ | 100 | ) |
| = | 9600 | + | 96 | a | + | 12000 | × | 1 | + | 12000 | a | ÷ | 100 | + | 240 | a | ( | 1 | + | a | ÷ | 100 | ) |
| = | 9600 | + | 96 | a | + | 12000 | + | 120 | a | + | 240 | a | ( | 1 | + | a | ÷ | 100 | ) |
| = | 21600 | + | 216 | a | + | 240 | a | ( | 1 | + | a | ÷ | 100 | ) |
| = | 21600 | + | 216 | a | + | 240 | a | × | 1 | + | 240 | a | a | ÷ | 100 |
| = | 21600 | + | 216 | a | + | 240 | a | + | 12 5 | a | a |
| = | 21600 | + | 456 | a | + | 12 5 | a | a |
| 21600 | + | 456 | a | + | 12 5 | a | a | = | 21600 | ( | 1 | + | 20 | ÷ | 9 | × | a | ÷ | 100 | ) |
| Right side of the equation = | 21600 | × | 1 | + | 21600 | × | 20 | ÷ | 9 | × | a | ÷ | 100 |
| = | 21600 | + | 480 | a |
| 21600 | + | 456 | a | + | 12 5 | a | a | = | 21600 | + | 480 | a |