| ( | 40 | − | 4 | x | ) | ( | 26 | − | 2 | x | ) | = | 144 | × | 6 |
| 方程左边 = | 40 | ( | 26 | − | 2 | x | ) | − | 4 | x | ( | 26 | − | 2 | x | ) |
| = | 40 | × | 26 | − | 40 | × | 2 | x | − | 4 | x | ( | 26 | − | 2 | x | ) |
| = | 1040 | − | 80 | x | − | 4 | x | ( | 26 | − | 2 | x | ) |
| = | 1040 | − | 80 | x | − | 4 | x | × | 26 | + | 4 | x | × | 2 | x |
| = | 1040 | − | 80 | x | − | 104 | x | + | 8 | x | x |
| = | 1040 | − | 184 | x | + | 8 | x | x |
| 1040 | − | 184 | x | + | 8 | x | x | = | 144 | × | 6 |
| 方程右边 = | 864 |
| 1040 | − | 184 | x | + | 8 | x | x | = | 864 |