| ( | 2200 | m | + | 2200 | ) | ( | 4 | − | 2 | m | ) | = | 6600 |
| Left side of the equation = | 2200 | m | ( | 4 | − | 2 | m | ) | + | 2200 | ( | 4 | − | 2 | m | ) |
| = | 2200 | m | × | 4 | − | 2200 | m | × | 2 | m | + | 2200 | ( | 4 | − | 2 | m | ) |
| = | 8800 | m | − | 4400 | m | m | + | 2200 | ( | 4 | − | 2 | m | ) |
| = | 8800 | m | − | 4400 | m | m | + | 2200 | × | 4 | − | 2200 | × | 2 | m |
| = | 8800 | m | − | 4400 | m | m | + | 8800 | − | 4400 | m |
| = | 4400 | m | − | 4400 | m | m | + | 8800 |
| 4400 | m | − | 4400 | m | m | + | 8800 | = | 6600 |