| ( | 8 5 | x | + | 5 | ) | ÷ | 9 10 | × | 3 5 | × | 9 10 | − | 5 | − | 4 5 | x | = | 0 |
| 方程左边 = | ( | 8 5 | x | + | 5 | ) | × | 3 5 | − | 5 | − | 4 5 | x |
| ( | 8 5 | x | + | 5 | ) | × | 3 5 | − | 5 | − | 4 5 | x | = | 0 |
| 方程左边 = | 8 5 | x | × | 3 5 | + | 5 | × | 3 5 | − | 5 | − | 4 5 | x |
| = | 24 25 | x | + | 3 | − | 5 | − | 4 5 | x |
| = | 4 25 | x | − | 2 |
4 25 | x | − | 2 | = | 0 |
4 25 | x | = | 0 | + | 2 |
4 25 | x | = | 2 |
| x | = | 2 | ÷ | 4 25 |
| = | 2 | × | 25 4 |
| = | 1 | × | 25 2 |
| x | = | 25 2 |
| x | = | 12.5 |