| 250 | ( | 1 | − | 20 100 | ) | ( | 1 | + | x | ) | = | 260 |
| 方程左边 = | 250 | × | 1 | ( | 1 | + | x | ) | − | 250 | × | 20 100 | ( | 1 | + | x | ) |
| = | 250 | ( | 1 | + | x | ) | − | 50 | ( | 1 | + | x | ) |
| = | 250 | × | 1 | + | 250 | x | − | 50 | ( | 1 | + | x | ) |
| = | 250 | + | 250 | x | − | 50 | ( | 1 | + | x | ) |
| = | 250 | + | 250 | x | − | 50 | × | 1 | − | 50 | x |
| = | 250 | + | 250 | x | − | 50 | − | 50 | x |
| = | 200 | + | 200 | x |
| 200 | + | 200 | x | = | 260 |
| 200 | x | = | 260 | − | 200 |
| 200 | x | = | 60 |
| x | = | 60 | ÷ | 200 |
| = | 60 | × | 1 200 |
| = | 3 | × | 1 10 |
| x | = | 3 10 |
| x | = | 0.3 |