| ( | 3 | − | m | ) | ( | 3 | − | m | ) | + | ( | 3 | m | + | 3 | ) | ( | 3 | m | + | 3 | ) | = | 288 | ÷ | 5 |
| 方程左边 = | 3 | ( | 3 | − | m | ) | − | m | ( | 3 | − | m | ) | + | ( | 3 | m | + | 3 | ) | ( | 3 | m | + | 3 | ) |
| = | 3 | × | 3 | − | 3 | m | − | m | ( | 3 | − | m | ) | + | ( | 3 | m | + | 3 | ) | ( | 3 | m | + | 3 | ) |
| = | 9 | − | 3 | m | − | m | ( | 3 | − | m | ) | + | ( | 3 | m | + | 3 | ) | ( | 3 | m | + | 3 | ) |
| = | 9 | − | 3 | m | − | m | × | 3 | + | m | m | + | ( | 3 | m | + | 3 | ) | ( | 3 | m | + | 3 | ) |
| = | 9 | − | 6 | m | + | m | m | + | ( | 3 | m | + | 3 | ) | ( | 3 | m | + | 3 | ) |
| = | 9 | − | 6 | m | + | m | m | + | 3 | m | ( | 3 | m | + | 3 | ) | + | 3 | ( | 3 | m | + | 3 | ) |
| = | 9 | − | 6 | m | + | m | m | + | 3 | m | × | 3 | m | + | 3 | m | × | 3 |
| = | 9 | − | 6 | m | + | m | m | + | 9 | m | m | + | 9 | m | + | 3 | ( | 3 | m | + | 3 | ) |
| = | 9 | + | 3 | m | + | m | m | + | 9 | m | m | + | 3 | ( | 3 | m | + | 3 | ) |
| = | 9 | + | 3 | m | + | m | m | + | 9 | m | m | + | 3 | × | 3 | m | + | 3 |
| = | 9 | + | 3 | m | + | m | m | + | 9 | m | m | + | 9 | m | + | 9 |
| = | 18 | + | 12 | m | + | m | m | + | 9 | m | m |
| 18 | + | 12 | m | + | m | m | + | 9 | m | m | = | 288 | ÷ | 5 |
| 方程右边 = | 288 5 |
| 18 | + | 12 | m | + | m | m | + | 9 | m | m | = | 288 5 |