| ( | 56 | ( | 1 | + | 20 100 | ) | ) | + | ( | 7 100 | x | ) | = | x |
| 方程左边 = | 56 | ( | 1 | + | 20 100 | ) | + | ( | 7 100 | x | ) |
| = | 56 | × | 1 | + | 56 | × | 20 100 | + | ( | 7 100 | x | ) |
| = | 56 | + | 56 5 | + | ( | 7 100 | x | ) |
| = | 336 5 | + | ( | 7 100 | x | ) |
| = | 336 5 | + | 7 100 | x |
336 5 | + | 7 100 | x | = | x |
7 100 | x | − | x | = | - | 336 5 |
| - | 93 100 | x | = | - | 336 5 |
336 5 | = | 93 100 | x |
93 100 | x | = | 336 5 |
| x | = | 336 5 | ÷ | 93 100 |
| = | 336 5 | × | 100 93 |
| = | 112 | × | 20 31 |
| x | = | 2240 31 |
| x | = | 72.258065 |