| ( | 10 | + | 2 | x | ) | ( | 76 | − | 4 | x | ) | = | 1080 |
| 方程左边 = | 10 | ( | 76 | − | 4 | x | ) | + | 2 | x | ( | 76 | − | 4 | x | ) |
| = | 10 | × | 76 | − | 10 | × | 4 | x | + | 2 | x | ( | 76 | − | 4 | x | ) |
| = | 760 | − | 40 | x | + | 2 | x | ( | 76 | − | 4 | x | ) |
| = | 760 | − | 40 | x | + | 2 | x | × | 76 | − | 2 | x | × | 4 | x |
| = | 760 | − | 40 | x | + | 152 | x | − | 8 | x | x |
| = | 760 | + | 112 | x | − | 8 | x | x |
| 760 | + | 112 | x | − | 8 | x | x | = | 1080 |