| ( | x | − | 3 10 | x | ) | ( | 1 | + | 3 2 | ) | − | x | = | 2250 |
| 方程左边 = | x | ( | 1 | + | 3 2 | ) | − | 3 10 | x | ( | 1 | + | 3 2 | ) | − | x |
| = | x | × | 1 | + | x | × | 3 2 | − | 3 10 | x | ( | 1 | + | 3 2 | ) | − | x |
| = | 3 2 | x | − | 3 10 | x | ( | 1 | + | 3 2 | ) |
| = | 3 2 | x | − | 3 10 | x | × | 1 | − | 3 10 | x | × | 3 2 |
| = | 3 2 | x | − | 3 10 | x | − | 9 20 | x |
| = | 3 4 | x |
3 4 | x | = | 2250 |
| x | = | 2250 | ÷ | 3 4 |
| = | 2250 | × | 4 3 |
| = | 750 | × | 4 |
| x | = | 3000 |