| 100 | ( | 1 | − | m | ) | × | 30 | + | 200 | ( | 1 | + | 2 | m | ) | ( | 30 | ( | 1 | − | m | ) | ) | = | 7000 |
| Left side of the equation = | 3000 | ( | 1 | − | m | ) | + | 200 | ( | 1 | + | 2 | m | ) | ( | 30 | ( | 1 | − | m | ) | ) |
| 3000 | ( | 1 | − | m | ) | + | 200 | ( | 1 | + | 2 | m | ) | ( | 30 | ( | 1 | − | m | ) | ) | = | 7000 |
| Left side of the equation = | 3000 | × | 1 | − | 3000 | m | + | 200 | ( | 1 | + | 2 | m | ) | ( | 30 | ( | 1 | − | m | ) | ) |
| = | 3000 | − | 3000 | m | + | 200 | ( | 1 | + | 2 | m | ) | ( | 30 | ( | 1 | − | m | ) | ) |
| = | 3000 | − | 3000 | m | + | 200 | × | 1 | ( | 30 | ( | 1 | − | m | ) | ) | + | 200 | × | 2 | m | ( | 30 | ( | 1 | − | m | ) | ) |
| = | 3000 | − | 3000 | m | + | 200 | ( | 30 | ( | 1 | − | m | ) | ) | + | 400 | m | ( | 30 | ( | 1 | − | m | ) | ) |
| = | 3000 | − | 3000 | m | + | 200 | × | 30 | ( | 1 | − | m | ) | + | 400 | m | ( | 30 | ( | 1 | − | m | ) | ) |
| = | 3000 | − | 3000 | m | + | 6000 | ( | 1 | − | m | ) | + | 400 | m | ( | 30 | ( | 1 | − | m | ) | ) |
| = | 3000 | − | 3000 | m | + | 6000 | × | 1 | − | 6000 | m | + | 400 | m | ( | 30 | ( | 1 | − | m | ) | ) |
| = | 3000 | − | 3000 | m | + | 6000 | − | 6000 | m | + | 400 | m | ( | 30 | ( | 1 | − | m | ) | ) |
| = | 9000 | − | 9000 | m | + | 400 | m | ( | 30 | ( | 1 | − | m | ) | ) |
| = | 9000 | − | 9000 | m | + | 400 | m | × | 30 | ( | 1 | − | m | ) |
| = | 9000 | − | 9000 | m | + | 12000 | m | ( | 1 | − | m | ) |
| = | 9000 | − | 9000 | m | + | 12000 | m | × | 1 | − | 12000 | m | m |
| = | 9000 | − | 9000 | m | + | 12000 | m | − | 12000 | m | m |
| = | 9000 | + | 3000 | m | − | 12000 | m | m |
| 9000 | + | 3000 | m | − | 12000 | m | m | = | 7000 |