| 500 | + | 500 | ( | x | + | 1 | ) | + | 500 | ( | x | + | 1 | ) | × | 2 | = | 1665 |
| 方程左边 = | 500 | + | 500 | ( | x | + | 1 | ) | + | 1000 | ( | x | + | 1 | ) |
| 500 | + | 500 | ( | x | + | 1 | ) | + | 1000 | ( | x | + | 1 | ) | = | 1665 |
| 方程左边 = | 500 | + | 500 | x | + | 500 | × | 1 | + | 1000 | ( | x | + | 1 | ) |
| = | 500 | + | 500 | x | + | 500 | + | 1000 | ( | x | + | 1 | ) |
| = | 1000 | + | 500 | x | + | 1000 | ( | x | + | 1 | ) |
| = | 1000 | + | 500 | x | + | 1000 | x | + | 1000 | × | 1 |
| = | 1000 | + | 500 | x | + | 1000 | x | + | 1000 |
| = | 2000 | + | 1500 | x |
| 2000 | + | 1500 | x | = | 1665 |
| 1500 | x | = | 1665 | − | 2000 |
| 1500 | x | = | - | 335 |
| x | = | - | 335 | ÷ | 1500 |
| = | - | 335 | × | 1 1500 |
| = | - | 67 | × | 1 300 |
| x | = | - | 67 300 |
| x | = | - 0.223333 |