| - | 16 | ( | 1 | − | 4 | x | ) | − | 4 | ( | 1 | − | 2 | x | ) | = | 0 |
| 方程左边 = | - | 16 | × | 1 | + | 16 | × | 4 | x | − | 4 | ( | 1 | − | 2 | x | ) |
| = | - | 16 | + | 64 | x | − | 4 | ( | 1 | − | 2 | x | ) |
| = | - | 16 | + | 64 | x | − | 4 | × | 1 | + | 4 | × | 2 | x |
| = | - | 16 | + | 64 | x | − | 4 | + | 8 | x |
| = | - | 20 | + | 72 | x |
| - | 20 | + | 72 | x | = | 0 |
| 72 | x | = | 0 | + | 20 |
| 72 | x | = | 20 |
| x | = | 20 | ÷ | 72 |
| = | 20 | × | 1 72 |
| = | 5 | × | 1 18 |
| x | = | 5 18 |
| x | = | 0.277778 |