| 4 | + | 2 | m | = | 8 | + | 1 2 | ( | 4 | + | m | ) | ( | 4 | − | 1 2 | m | ) | + | 1 2 | ( | 1 2 | m | − | 2 | ) |
| 方程右边 = | 8 | + | 1 2 | × | 4 | ( | 4 | − | 1 2 | m | ) | + | 1 2 | m | ( | 4 | − | 1 2 | m | ) | + | 1 2 | ( | 1 2 | m | − | 2 | ) |
| = | 8 | + | 2 | ( | 4 | − | 1 2 | m | ) | + | 1 2 | m | ( | 4 | − | 1 2 | m | ) | + | 1 2 | ( | 1 2 | m | − | 2 | ) |
| = | 8 | + | 2 | × | 4 | − | 2 | × | 1 2 | m | + | 1 2 | m | ( | 4 | − | 1 2 | m | ) | + | 1 2 | ( | 1 2 | m | − | 2 | ) |
| = | 8 | + | 8 | − | 1 | m | + | 1 2 | m | ( | 4 | − | 1 2 | m | ) | + | 1 2 | ( | 1 2 | m | − | 2 | ) |
| = | 16 | − | 1 | m | + | 1 2 | m | ( | 4 | − | 1 2 | m | ) | + | 1 2 | ( | 1 2 | m | − | 2 | ) |
| = | 16 | − | 1 | m | + | 1 2 | m | × | 4 | − | 1 2 | m | × | 1 2 | m | + | 1 2 | ( | 1 2 | m | − | 2 | ) |
| = | 16 | − | 1 | m | + | 2 | m | − | 1 4 | m | m | + | 1 2 | ( | 1 2 | m | − | 2 | ) |
| = | 16 | + | 1 | m | − | 1 4 | m | m | + | 1 2 | ( | 1 2 | m | − | 2 | ) |
| = | 16 | + | 1 | m | − | 1 4 | m | m | + | 1 2 | × | 1 2 | m | − | 1 2 | × | 2 |
| = | 16 | + | 1 | m | − | 1 4 | m | m | + | 1 4 | m | − | 1 |
| = | 15 | + | 5 4 | m | − | 1 4 | m | m |
| 4 | + | 2 | m | = | 15 | + | 5 4 | m | − | 1 4 | m | m |