| ( | 10 | − | x | ) | ( | 200 | + | 45 | x | ) | = | 0 |
| 方程左边 = | 10 | ( | 200 | + | 45 | x | ) | − | x | ( | 200 | + | 45 | x | ) |
| = | 10 | × | 200 | + | 10 | × | 45 | x | − | x | ( | 200 | + | 45 | x | ) |
| = | 2000 | + | 450 | x | − | x | ( | 200 | + | 45 | x | ) |
| = | 2000 | + | 450 | x | − | x | × | 200 | − | x | × | 45 | x |
| = | 2000 | + | 250 | x | − | x | × | 45 | x |
| 2000 | + | 250 | x | − | x | × | 45 | x | = | 0 |
| x1= | - | 40 9 |
| x2=10 |