| x | + | 100 | + | 2 5 | x | = | 4 | ( | 27 | + | 4 5 | x | ) |
| 方程左边 = | 7 5 | x | + | 100 |
7 5 | x | + | 100 | = | 4 | ( | 27 | + | 4 5 | x | ) |
| 方程右边 = | 4 | × | 27 | + | 4 | × | 4 5 | x |
| = | 108 | + | 16 5 | x |
7 5 | x | + | 100 | = | 108 | + | 16 5 | x |
7 5 | x | − | 16 5 | x | = | 108 | − | 100 |
| - | 9 5 | x | = | 108 | − | 100 |
| - | 9 5 | x | = | 8 |
| - | 8 | = | 9 5 | x |
9 5 | x | = | - | 8 |
| x | = | - | 8 | ÷ | 9 5 |
| = | - | 8 | × | 5 9 |
| x | = | - | 40 9 |
| x | = | - 4.444444 |