| ( | 4 | − | ( | 2 | ÷ | m | ) | ) | ( | - | 2 | m | ÷ | 5 | ) | = | - | ( | 2 | m | − | 8 | ) | ( | - | 13 | m | ÷ | 10 | ) |
| 4 | ( | - | 2 | m | ÷ | 5 | ) | − | ( | 2 | ÷ | m | ) | ( | - | 2 | m | ÷ | 5 | ) | = | - | ( | 2 | m | − | 8 | ) | ( | - | 13 | m | ÷ | 10 | ) |
| 4 | ( | - | 2 | m | ÷ | 5 | ) | − | ( | 2 | ÷ | m | ) | ( | - | 2 | m | ÷ | 5 | ) | = | - | 2 | m | ( | - | 13 | m | ÷ | 10 | ) | + | 8 | ( | - | 13 | m | ÷ | 10 | ) |
| - | 4 | × | 2 | m | ÷ | 5 | − | ( | 2 | ÷ | 1 | ) | ( | - | 2 | × | 1 | ÷ | 5 | ) | = | - | 2 | m | ( | - | 13 | m | ÷ | 10 | ) | + | 8 | ( | - | 13 | m | ÷ | 10 | ) |
| - | 4 | × | 2 | m | ÷ | 5 | − | ( | 2 | ÷ | 1 | ) | ( | - | 2 | × | 1 | ÷ | 5 | ) | = | 2 | m | × | 13 | m | ÷ | 10 | + | 8 | ( | - | 13 | m | ÷ | 10 | ) |
| - | 8 5 | m | − | ( | 2 | ÷ | 1 | ) | ( | - | 2 | × | 1 | ÷ | 5 | ) | = | 13 5 | m | m | + | 8 | ( | - | 13 | m | ÷ | 10 | ) |
| - | 8 5 | m | − | 2 | ÷ | 1 | × | ( | - | 2 | × | 1 | ÷ | 5 | ) | = | 13 5 | m | m | + | 8 | ( | - | 13 | m | ÷ | 10 | ) |
| - | 8 5 | m | − | 2 | ÷ | 1 | × | ( | - | 2 | × | 1 | ÷ | 5 | ) | = | 13 5 | m | m | − | 8 | × | 13 | m | ÷ | 10 |
| - | 8 5 | m | − | 2 | ( | - | 2 | × | 1 | ÷ | 5 | ) | = | 13 5 | m | m | − | 52 5 | m |
| - | 8 5 | m | + | 2 | × | 2 | × | 1 | ÷ | 5 | = | 13 5 | m | m | − | 52 5 | m |
| - | 8 5 | m | + | 4 5 | = | 13 5 | m | m | − | 52 5 | m |