21 20 | x | + | 58 | + | 15 | + | 5 | + | ( | 21 20 | x | + | 58 | + | 15 | + | 5 | ) | × | 3 20 | = | 183011 500 |
| 方程左边 = | 21 20 | x | + | 78 | + | ( | 21 20 | x | + | 58 | + | 15 | + | 5 | ) | × | 3 20 |
21 20 | x | + | 78 | + | ( | 21 20 | x | + | 58 | + | 15 | + | 5 | ) | × | 3 20 | = | 183011 500 |
| 方程左边 = | 21 20 | x | + | 78 | + | 21 20 | x | × | 3 20 | + | 58 | × | 3 20 | + | 15 | × | 3 20 | + | 5 | × | 3 20 |
| = | 21 20 | x | + | 78 | + | 63 400 | x | + | 87 10 | + | 9 4 | + | 3 4 |
| = | 483 400 | x | + | 897 10 |
483 400 | x | + | 897 10 | = | 183011 500 |
483 400 | x | = | 183011 500 | − | 897 10 |
483 400 | x | = | 138161 500 |
| x | = | 138161 500 | ÷ | 483 400 |
| = | 138161 500 | × | 400 483 |
| = | 138161 5 | × | 4 483 |
| x | = | 552644 2415 |
| x | = | 24028 105 |
| x | = | 228.838095 |