| ( | x | − | x | ÷ | 40 | ) | + | ( | x | − | 7870 | ) | = | 8200 | ÷ | 19 20 | + | 100 |
| 方程左边 = | x | − | x | ÷ | 40 | + | ( | x | − | 7870 | ) |
| = | 39 40 | x | + | ( | x | − | 7870 | ) |
| = | 39 40 | x | + | x | − | 7870 |
| = | 79 40 | x | − | 7870 |
79 40 | x | − | 7870 | = | 8200 | ÷ | 19 20 | + | 100 |
| 方程右边 = | 164000 19 | + | 100 |
| = | 165900 19 |
79 40 | x | − | 7870 | = | 165900 19 |
79 40 | x | = | 165900 19 | + | 7870 |
79 40 | x | = | 315430 19 |
| x | = | 315430 19 | ÷ | 79 40 |
| = | 315430 19 | × | 40 79 |
| x | = | 12617200 1501 |
| x | = | 8405.862758 |