| ( | - | 5 | m | m | + | 20 | m | ) | ÷ | 2 | × | ( | m | − | 1 | ) | ( | m | − | 1 | ) | = | 10 | m |
| Left side of the equation = | - | 5 | m | m | × | 1 2 | ( | m | − | 1 | ) | ( | m | − | 1 | ) | + | 20 | m | × | 1 2 | ( | m | − | 1 | ) | ( | m | − | 1 | ) |
| = | - | 5 2 | m | m | ( | m | − | 1 | ) | ( | m | − | 1 | ) | + | 10 | m | ( | m | − | 1 | ) | ( | m | − | 1 | ) |
| = | - | 5 2 | m | m | m | ( | m | − | 1 | ) | + | 5 2 | m | m | × | 1 | ( | m | − | 1 | ) | + | 10 | m |
| = | - | 5 2 | m | m | m | ( | m | − | 1 | ) | + | 5 2 | m | m | ( | m | − | 1 | ) | + | 10 | m | ( | m | − | 1 | ) |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | × | 1 | + | 5 2 | m |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m |
| = | - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m |
| - | 5 2 | m | m | m | m | + | 5 2 | m | m | m | + | 5 2 | m | m | = | 10 | m |