13 5 | x | + | ( | 23 | − | 10 | − | x | ) | × | 7 2 | = | 409 5 |
| 方程左边 = | 13 5 | x | + | 23 | × | 7 2 | − | 10 | × | 7 2 | − | x | × | 7 2 |
| = | 13 5 | x | + | 161 2 | − | 35 | − | x | × | 7 2 |
| = | - | 9 10 | x | + | 91 2 |
| - | 9 10 | x | + | 91 2 | = | 409 5 |
| - | 9 10 | x | = | 409 5 | − | 91 2 |
| - | 9 10 | x | = | 363 10 |
| - | 363 10 | = | 9 10 | x |
9 10 | x | = | - | 363 10 |
| x | = | - | 363 10 | ÷ | 9 10 |
| = | - | 363 10 | × | 10 9 |
| = | - | 121 | × | 1 3 |
| x | = | - | 121 3 |
| x | = | - 40.333333 |