| ( | 393 2 | + | 376 | ) | ÷ | 31 | × | x | + | 124 | ÷ | 31 | × | ( | x | + | 15 | ) | + | 124 | ÷ | 31 | × | ( | x | + | 30 | ) | = | 1223 |
| 方程左边 = | ( | 393 2 | + | 376 | ) | × | 1 31 | x | + | 4 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) |
| ( | 393 2 | + | 376 | ) | × | 1 31 | x | + | 4 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) | = | 1223 |
| 方程左边 = | 393 2 | × | 1 31 | x | + | 376 | × | 1 31 | x | + | 4 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) |
| = | 393 62 | x | + | 376 31 | x | + | 4 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) |
| = | 1145 62 | x | + | 4 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) |
| = | 1145 62 | x | + | 4 | x | + | 4 | × | 15 | + | 4 | ( | x | + | 30 | ) |
| = | 1145 62 | x | + | 4 | x | + | 60 | + | 4 | ( | x | + | 30 | ) |
| = | 1393 62 | x | + | 60 | + | 4 | ( | x | + | 30 | ) |
| = | 1393 62 | x | + | 60 | + | 4 | x | + | 4 | × | 30 |
| = | 1393 62 | x | + | 60 | + | 4 | x | + | 120 |
| = | 1641 62 | x | + | 180 |
1641 62 | x | + | 180 | = | 1223 |
1641 62 | x | = | 1223 | − | 180 |
1641 62 | x | = | 1043 |
| x | = | 1043 | ÷ | 1641 62 |
| = | 1043 | × | 62 1641 |
| x | = | 64666 1641 |
| x | = | 39.406459 |