1213 100 | c | = | ( | 7 2 | + | c | ) | × | 399 50 |
| 方程右边 = | 7 2 | × | 399 50 | + | c | × | 399 50 |
| = | 2793 100 | + | c | × | 399 50 |
1213 100 | c | = | 2793 100 | + | 399 50 | c |
1213 100 | c | − | 399 50 | c | = | 2793 100 |
83 20 | c | = | 2793 100 |
| c | = | 2793 100 | ÷ | 83 20 |
| = | 2793 100 | × | 20 83 |
| = | 2793 5 | × | 1 83 |
| c | = | 2793 415 |
| c | = | 6.73012 |