| 30 | ( | 1 | + | m | ) | ( | 1 | + | 1 2 | m | ) | = | 66 |
| Left side of the equation = | 30 | × | 1 | ( | 1 | + | 1 2 | m | ) | + | 30 | m | ( | 1 | + | 1 2 | m | ) |
| = | 30 | ( | 1 | + | 1 2 | m | ) | + | 30 | m | ( | 1 | + | 1 2 | m | ) |
| = | 30 | × | 1 | + | 30 | × | 1 2 | m | + | 30 | m | ( | 1 | + | 1 2 | m | ) |
| = | 30 | + | 15 | m | + | 30 | m | ( | 1 | + | 1 2 | m | ) |
| = | 30 | + | 15 | m | + | 30 | m | × | 1 | + | 30 | m | × | 1 2 | m |
| = | 30 | + | 15 | m | + | 30 | m | + | 15 | m | m |
| = | 30 | + | 45 | m | + | 15 | m | m |
| 30 | + | 45 | m | + | 15 | m | m | = | 66 |