| ( | 6 | − | 1 10 | m | ) | ( | 140 | + | 4 | m | ) | + | 12 | ( | 120 | − | 1 2 | m | ) | = | 2280 |
| Left side of the equation = | 6 | ( | 140 | + | 4 | m | ) | − | 1 10 | m | ( | 140 | + | 4 | m | ) | + | 12 | ( | 120 | − | 1 2 | m | ) |
| = | 6 | × | 140 | + | 6 | × | 4 | m | − | 1 10 | m | ( | 140 | + | 4 | m | ) | + | 12 | ( | 120 | − | 1 2 | m | ) |
| = | 840 | + | 24 | m | − | 1 10 | m | ( | 140 | + | 4 | m | ) | + | 12 | ( | 120 | − | 1 2 | m | ) |
| = | 840 | + | 24 | m | − | 1 10 | m | × | 140 | − | 1 10 | m | × | 4 | m | + | 12 | ( | 120 | − | 1 2 | m | ) |
| = | 840 | + | 24 | m | − | 14 | m | − | 2 5 | m | m | + | 12 | ( | 120 | − | 1 2 | m | ) |
| = | 840 | + | 10 | m | − | 2 5 | m | m | + | 12 | ( | 120 | − | 1 2 | m | ) |
| = | 840 | + | 10 | m | − | 2 5 | m | m | + | 12 | × | 120 | − | 12 | × | 1 2 | m |
| = | 840 | + | 10 | m | − | 2 5 | m | m | + | 1440 | − | 6 | m |
| = | 2280 | + | 4 | m | − | 2 5 | m | m |
| 2280 | + | 4 | m | − | 2 5 | m | m | = | 2280 |