| ( | ( | m | ÷ | 2 | ) | + | 40 | ) | ÷ | ( | m | ÷ | 10 | ) | = | ( | ( | m | ÷ | 2 | ) | − | 40 | ) | ÷ | ( | m | ÷ | 15 | ) |
| Multiply both sides of the equation by: | ( | m | ÷ | 10 | ) | , | ( | 1 | ÷ | 15 | ) |
| ( | ( | m | ÷ | 2 | ) | + | 40 | ) | ( | 1 | ÷ | 15 | ) | = | ( | ( | m | ÷ | 2 | ) | − | 40 | ) | ( | 1 | ÷ | 10 | ) |
| ( | m | ÷ | 2 | ) | ( | 1 | ÷ | 15 | ) | + | 40 | ( | 1 | ÷ | 15 | ) | = | ( | ( | m | ÷ | 2 | ) | − | 40 | ) | ( | 1 | ÷ | 10 | ) |
| ( | m | ÷ | 2 | ) | ( | 1 | ÷ | 15 | ) | + | 40 | ( | 1 | ÷ | 15 | ) | = | ( | m | ÷ | 2 | ) | ( | 1 | ÷ | 10 | ) | − | 40 | ( | 1 | ÷ | 10 | ) |
| m | ÷ | 2 | × | ( | 1 | ÷ | 15 | ) | + | 40 | ( | 1 | ÷ | 15 | ) | = | ( | m | ÷ | 2 | ) | ( | 1 | ÷ | 10 | ) | − | 40 | ( | 1 | ÷ | 10 | ) |
| m | ÷ | 2 | × | ( | 1 | ÷ | 15 | ) | + | 40 | ( | 1 | ÷ | 15 | ) | = | m | ÷ | 2 | × | ( | 1 | ÷ | 10 | ) | − | 40 | ( | 1 | ÷ | 10 | ) |
| m | × | 1 2 | × | 1 | ÷ | 15 | + | 40 | ( | 1 | ÷ | 15 | ) | = | m | × | 1 2 | ( | 1 | ÷ | 10 | ) | − | 40 | ( | 1 | ÷ | 10 | ) |
| m | × | 1 2 | × | 1 | ÷ | 15 | + | 40 | ( | 1 | ÷ | 15 | ) | = | m | × | 1 2 | × | 1 | ÷ | 10 | − | 40 | ( | 1 | ÷ | 10 | ) |
| m | × | 1 30 | + | 40 | ( | 1 | ÷ | 15 | ) | = | m | × | 1 20 | − | 40 | ( | 1 | ÷ | 10 | ) |
1 30 | m | + | 40 | × | 1 | ÷ | 15 | = | 1 20 | m | − | 40 | ( | 1 | ÷ | 10 | ) |
1 30 | m | + | 40 | × | 1 | ÷ | 15 | = | 1 20 | m | − | 40 | × | 1 | ÷ | 10 |
1 30 | m | + | 8 3 | = | 1 20 | m | − | 4 |
1 30 | m | − | 1 20 | m | = | - | 4 | − | 8 3 |
| - | 1 60 | m | = | - | 4 | − | 8 3 |
| - | 1 60 | m | = | - | 20 3 |
20 3 | = | 1 60 | m |
1 60 | m | = | 20 3 |
| m | = | 20 3 | ÷ | 1 60 |
| = | 20 3 | × | 60 |
| = | 20 | × | 20 |
| m | = | 400 |