| 1000 | ( | 1 | + | m | ÷ | 2 100 | ) | × | 500 | ( | 1 | + | m | ) | = | 660000 |
| Left side of the equation = | 500000 | ( | 1 | + | m | ÷ | 2 100 | ) | ( | 1 | + | m | ) |
| 500000 | ( | 1 | + | m | ÷ | 2 100 | ) | ( | 1 | + | m | ) | = | 660000 |
| Left side of the equation = | 500000 | × | 1 | ( | 1 | + | m | ) | + | 500000 | m | ÷ | 2 100 | × | ( | 1 | + | m | ) |
| = | 500000 | ( | 1 | + | m | ) | + | 25000000 | m | ( | 1 | + | m | ) |
| = | 500000 | × | 1 | + | 500000 | m | + | 25000000 | m | ( | 1 | + | m | ) |
| = | 500000 | + | 500000 | m | + | 25000000 | m | ( | 1 | + | m | ) |
| = | 500000 | + | 500000 | m | + | 25000000 | m | × | 1 | + | 25000000 | m | m |
| = | 500000 | + | 500000 | m | + | 25000000 | m | + | 25000000 | m | m |
| = | 500000 | + | 25500000 | m | + | 25000000 | m | m |
| 500000 | + | 25500000 | m | + | 25000000 | m | m | = | 660000 |