| 25 | × | 10 | + | 5 | ( | x | − | 10 | ) | = | 9 10 | ( | 25 | × | 10 | + | 5 | x | ) |
| 方程左边 = | 250 | + | 5 | ( | x | − | 10 | ) |
| 250 | + | 5 | ( | x | − | 10 | ) | = | 9 10 | ( | 25 | × | 10 | + | 5 | x | ) |
| 方程左边 = | 250 | + | 5 | x | − | 5 | × | 10 |
| = | 250 | + | 5 | x | − | 50 |
| = | 200 | + | 5 | x |
| 200 | + | 5 | x | = | 9 10 | ( | 25 | × | 10 | + | 5 | x | ) |
| 方程右边 = | 9 10 | × | 25 | × | 10 | + | 9 10 | × | 5 | x |
| = | 225 | + | 9 2 | x |
| 200 | + | 5 | x | = | 225 | + | 9 2 | x |
| 5 | x | − | 9 2 | x | = | 225 | − | 200 |
1 2 | x | = | 225 | − | 200 |
1 2 | x | = | 25 |
| x | = | 25 | ÷ | 1 2 |
| = | 25 | × | 2 |
| x | = | 50 |