| X | = | 21 | + | ( | X | ÷ | ( | 1 | + | 17 100 | ) | × | 17 100 | ) | + | X | × | 5 100 | + | X | × | 10 100 |
| X | = | 21 | + | X | ÷ | ( | 1 | + | 17 100 | ) | × | 17 100 | + | X | × | 5 100 | + | X | × | 10 100 |
| X | = | 21 | + | X | ÷ | ( | 1 | + | 17 100 | ) | × | 17 100 | + | 3 20 | X |
| 方程两边同时乘以: | ( | 1 | + | 17 100 | ) |
| X | ( | 1 | + | 17 100 | ) | = | 21 | ( | 1 | + | 17 100 | ) | + | X | × | 17 100 | + | 3 20 | X | ( | 1 | + | 17 100 | ) |
| X | × | 1 | + | X | × | 17 100 | = | 21 | ( | 1 | + | 17 100 | ) | + | X | × | 17 100 | + | 3 20 | X | ( | 1 | + | 17 100 | ) |
| X | × | 1 | + | X | × | 17 100 | = | 21 | × | 1 | + | 21 | × | 17 100 | + | X | × | 17 100 | + | 3 20 | X | ( | 1 | + | 17 100 | ) |
| X | × | 1 | + | X | × | 17 100 | = | 21 | + | 357 100 | + | X | × | 17 100 | + | 3 20 | X | ( | 1 | + | 17 100 | ) |
117 100 | X | = | 2457 100 | + | 17 100 | X | + | 3 20 | X | ( | 1 | + | 17 100 | ) |
117 100 | X | = | 2457 100 | + | 17 100 | X | + | 3 20 | X | × | 1 | + | 3 20 | X | × | 17 100 |
117 100 | X | = | 2457 100 | + | 17 100 | X | + | 3 20 | X | + | 51 2000 | X |
117 100 | X | = | 2457 100 | + | 691 2000 | X |
117 100 | X | − | 691 2000 | X | = | 2457 100 |
1649 2000 | X | = | 2457 100 |
| X | = | 2457 100 | ÷ | 1649 2000 |
| = | 2457 100 | × | 2000 1649 |
| = | 2457 | × | 20 1649 |
| X | = | 49140 1649 |
| X | = | 29.799879 |