| 800 | ( | 1 | + | 2 | x | ÷ | 100 | ) | ( | 1 | + | x | ÷ | 100 | ) | + | 360 | = | 2100 |
| Left side of the equation = | 800 | × | 1 | ( | 1 | + | x | ÷ | 100 | ) | + | 800 | × | 2 | x | ÷ | 100 | × | ( | 1 | + | x | ÷ | 100 | ) | + | 360 |
| = | 800 | ( | 1 | + | x | ÷ | 100 | ) | + | 16 | x | ( | 1 | + | x | ÷ | 100 | ) | + | 360 |
| = | 800 | × | 1 | + | 800 | x | ÷ | 100 | + | 16 | x | ( | 1 | + | x | ÷ | 100 | ) | + | 360 |
| = | 800 | + | 8 | x | + | 16 | x | ( | 1 | + | x | ÷ | 100 | ) | + | 360 |
| = | 1160 | + | 8 | x | + | 16 | x | ( | 1 | + | x | ÷ | 100 | ) |
| = | 1160 | + | 8 | x | + | 16 | x | × | 1 | + | 16 | x | x | ÷ | 100 |
| = | 1160 | + | 8 | x | + | 16 | x | + | 4 25 | x | x |
| = | 1160 | + | 24 | x | + | 4 25 | x | x |
| 1160 | + | 24 | x | + | 4 25 | x | x | = | 2100 |