| ( | 40 | + | x | ) | × | 33 | = | 40 | × | 27 | + | 450 | x |
| 方程左边 = | 40 | × | 33 | + | x | × | 33 |
| = | 1320 | + | x | × | 33 |
| 1320 | + | 33 | x | = | 40 | × | 27 | + | 450 | x |
| 方程右边 = | 1080 | + | 450 | x |
| 1320 | + | 33 | x | = | 1080 | + | 450 | x |
| 33 | x | − | 450 | x | = | 1080 | − | 1320 |
| - | 417 | x | = | 1080 | − | 1320 |
| - | 417 | x | = | - | 240 |
| 240 | = | 417 | x |
| 417 | x | = | 240 |
| x | = | 240 | ÷ | 417 |
| = | 240 | × | 1 417 |
| = | 80 | × | 1 139 |
| x | = | 80 139 |
| x | = | 0.57554 |