| 5 | ( | 3 | − | x | ) | − | 12 | ( | 5 | − | 2 | x | ) | = | - | 17 |
| 方程左边 = | 5 | × | 3 | − | 5 | x | − | 12 | ( | 5 | − | 2 | x | ) |
| = | 15 | − | 5 | x | − | 12 | ( | 5 | − | 2 | x | ) |
| = | 15 | − | 5 | x | − | 12 | × | 5 | + | 12 | × | 2 | x |
| = | 15 | − | 5 | x | − | 60 | + | 24 | x |
| = | - | 45 | + | 19 | x |
| - | 45 | + | 19 | x | = | - | 17 |
| 19 | x | = | - | 17 | + | 45 |
| 19 | x | = | 28 |
| x | = | 28 | ÷ | 19 |
| = | 28 | × | 1 19 |
| x | = | 28 19 |
| x | = | 1.473684 |