2561 25 | ( | 20 | + | k | ) | = | 60 | ( | 20 | − | k | ) |
| 方程左边 = | 2561 25 | × | 20 | + | 2561 25 | k |
| = | 10244 5 | + | 2561 25 | k |
10244 5 | + | 2561 25 | k | = | 60 | ( | 20 | − | k | ) |
| 方程右边 = | 60 | × | 20 | − | 60 | k |
| = | 1200 | − | 60 | k |
10244 5 | + | 2561 25 | k | = | 1200 | − | 60 | k |
2561 25 | k | + | 60 | k | = | 1200 | − | 10244 5 |
4061 25 | k | = | 1200 | − | 10244 5 |
4061 25 | k | = | - | 4244 5 |
| k | = | - | 4244 5 | ÷ | 4061 25 |
| = | - | 4244 5 | × | 25 4061 |
| = | - | 4244 | × | 5 4061 |
| k | = | - | 21220 4061 |
| k | = | - 5.225314 |