| ( | 25 | + | m | ) | − | ( | 25 | + | m | ) | − | ( | 25 | + | m | ) | − | 18 | + | m | = | 10 |
| Left side of the equation = | 25 | + | m | − | ( | 25 | + | m | ) | − | ( | 25 | + | m | ) | − | 18 | + | m |
| = | 7 | + | 2 | m | − | ( | 25 | + | m | ) | − | ( | 25 | + | m | ) |
| = | 7 | + | 2 | m | − | 25 | − | m | − | ( | 25 | + | m | ) |
| = | - | 18 | + | 1 | m | − | ( | 25 | + | m | ) |
| = | - | 18 | + | 1 | m | − | 25 | − | m |
| = | - | 43 | + | 0 | m |
| - | 43 | + | 0 | m | = | 10 |
| = | 10 | + | 43 |