| 60 | ( | 25 | − | 20 | ) | + | ( | 40 | − | 35 | ) | x | + | ( | 40 | × | 9 10 | ) | ( | 40 | − | x | ) | = | 380 |
| 方程左边 = | 60 | × | 25 | − | 60 | × | 20 | + | ( | 40 | − | 35 | ) | x | + | ( | 40 | × | 9 10 | ) | ( | 40 | − | x | ) |
| = | 1500 | − | 1200 | + | ( | 40 | − | 35 | ) | x | + | ( | 40 | × | 9 10 | ) | ( | 40 | − | x | ) |
| = | 300 | + | ( | 40 | − | 35 | ) | x | + | ( | 40 | × | 9 10 | ) | ( | 40 | − | x | ) |
| = | 300 | + | 40 | x | − | 35 | x | + | ( | 40 | × | 9 10 | ) | ( | 40 | − | x | ) |
| = | 300 | + | 5 | x | + | ( | 40 | × | 9 10 | ) | ( | 40 | − | x | ) |
| = | 300 | + | 5 | x | + | 40 | × | 9 10 | ( | 40 | − | x | ) |
| = | 300 | + | 5 | x | + | 36 | ( | 40 | − | x | ) |
| = | 300 | + | 5 | x | + | 36 | × | 40 | − | 36 | x |
| = | 300 | + | 5 | x | + | 1440 | − | 36 | x |
| = | 1740 | − | 31 | x |
| 1740 | − | 31 | x | = | 380 |
| - | 31 | x | = | 380 | − | 1740 |
| - | 31 | x | = | - | 1360 |
| 1360 | = | 31 | x |
| 31 | x | = | 1360 |
| x | = | 1360 | ÷ | 31 |
| = | 1360 | × | 1 31 |
| x | = | 1360 31 |
| x | = | 43.870968 |