| ( | 36 | − | 3 | x | ) | ( | 24 | − | 2 | x | ) | = | 600 |
| 方程左边 = | 36 | ( | 24 | − | 2 | x | ) | − | 3 | x | ( | 24 | − | 2 | x | ) |
| = | 36 | × | 24 | − | 36 | × | 2 | x | − | 3 | x | ( | 24 | − | 2 | x | ) |
| = | 864 | − | 72 | x | − | 3 | x | ( | 24 | − | 2 | x | ) |
| = | 864 | − | 72 | x | − | 3 | x | × | 24 | + | 3 | x | × | 2 | x |
| = | 864 | − | 72 | x | − | 72 | x | + | 6 | x | x |
| = | 864 | − | 144 | x | + | 6 | x | x |
| 864 | − | 144 | x | + | 6 | x | x | = | 600 |