| 150 | + | 5 | ( | x | − | 5 | ) | = | 9 10 | ( | 150 | + | 5 | x | ) |
| 方程左边 = | 150 | + | 5 | x | − | 5 | × | 5 |
| = | 150 | + | 5 | x | − | 25 |
| = | 125 | + | 5 | x |
| 125 | + | 5 | x | = | 9 10 | ( | 150 | + | 5 | x | ) |
| 方程右边 = | 9 10 | × | 150 | + | 9 10 | × | 5 | x |
| = | 135 | + | 9 2 | x |
| 125 | + | 5 | x | = | 135 | + | 9 2 | x |
| 5 | x | − | 9 2 | x | = | 135 | − | 125 |
1 2 | x | = | 135 | − | 125 |
1 2 | x | = | 10 |
| x | = | 10 | ÷ | 1 2 |
| = | 10 | × | 2 |
| x | = | 20 |