| 20 | ÷ | 6679 50 | + | 4 | ÷ | 45 | + | X | ÷ | 447 10 | + | ( | 56 | − | X | ) | ÷ | 1000 | = | 9 20 |
| 方程左边 = | 1000 6679 | + | 4 45 | + | X | × | 10 447 | + | ( | 56 | − | X | ) | × | 1 1000 |
| = | 71716 300555 | + | 10 447 | X | + | ( | 56 | − | X | ) | × | 1 1000 |
71716 300555 | + | 10 447 | X | + | ( | 56 | − | X | ) | × | 1 1000 | = | 9 20 |
| 方程左边 = | 71716 300555 | + | 10 447 | X | + | 56 | × | 1 1000 | − | X | × | 1 1000 |
| = | 71716 300555 | + | 10 447 | X | + | 7 125 | − | X | × | 1 1000 |
| = | 2213677 7513875 | + | 9553 447000 | X |
2213677 7513875 | + | 9553 447000 | X | = | 9 20 |
9553 447000 | X | = | 9 20 | − | 2213677 7513875 |
9553 447000 | X | = | 4670267 30055500 |
| X | = | 4670267 30055500 | ÷ | 9553 447000 |
| = | 4670267 30055500 | × | 447000 9553 |
| = | 4670267 20037 | × | 298 9553 |
| X | = | 1391739566 191413461 |
| X | = | 7.270855 |