| ( | 174 | + | 8 | x | ) | ( | 410 | + | 605 | x | ) | − | 700000 | = | 0 |
| 方程左边 = | 174 | ( | 410 | + | 605 | x | ) | + | 8 | x | ( | 410 | + | 605 | x | ) | − | 700000 |
| = | 174 | × | 410 | + | 174 | × | 605 | x | + | 8 | x | ( | 410 | + | 605 | x | ) | − | 700000 |
| = | 71340 | + | 105270 | x | + | 8 | x | ( | 410 | + | 605 | x | ) | − | 700000 |
| = | - | 628660 | + | 105270 | x | + | 8 | x | ( | 410 | + | 605 | x | ) |
| = | - | 628660 | + | 105270 | x | + | 8 | x | × | 410 | + | 8 | x | × | 605 | x |
| = | - | 628660 | + | 105270 | x | + | 3280 | x | + | 4840 | x | x |
| = | - | 628660 | + | 108550 | x | + | 4840 | x | x |
| - | 628660 | + | 108550 | x | + | 4840 | x | x | = | 0 |