| ( | 39331 | − | X | ) | × | 3 20 | ÷ | 2 | + | 1 5 | X | = | 398363 100 |
| 方程左边 = | ( | 39331 | − | X | ) | × | 3 40 | + | 1 5 | X |
| ( | 39331 | − | X | ) | × | 3 40 | + | 1 5 | X | = | 398363 100 |
| 方程左边 = | 39331 | × | 3 40 | − | X | × | 3 40 | + | 1 5 | X |
| = | 117993 40 | − | X | × | 3 40 | + | 1 5 | X |
| = | 117993 40 | + | 1 8 | X |
117993 40 | + | 1 8 | X | = | 398363 100 |
1 8 | X | = | 398363 100 | − | 117993 40 |
1 8 | X | = | 206761 200 |
| X | = | 206761 200 | ÷ | 1 8 |
| = | 206761 200 | × | 8 |
| = | 206761 25 | × | 1 |
| X | = | 206761 25 |
| X | = | 8270.44 |