| ( | 186 | + | 310 | ) | ÷ | 31 | × | x | + | 248 | ÷ | 31 | × | ( | x | + | 15 | ) | + | 124 | ÷ | 31 | × | ( | x | + | 30 | ) | = | 1766 |
| 方程左边 = | ( | 186 | + | 310 | ) | × | 1 31 | x | + | 8 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) |
| ( | 186 | + | 310 | ) | × | 1 31 | x | + | 8 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) | = | 1766 |
| 方程左边 = | 186 | × | 1 31 | x | + | 310 | × | 1 31 | x | + | 8 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) |
| = | 6 | x | + | 10 | x | + | 8 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) |
| = | 16 | x | + | 8 | ( | x | + | 15 | ) | + | 4 | ( | x | + | 30 | ) |
| = | 16 | x | + | 8 | x | + | 8 | × | 15 | + | 4 | ( | x | + | 30 | ) |
| = | 16 | x | + | 8 | x | + | 120 | + | 4 | ( | x | + | 30 | ) |
| = | 24 | x | + | 120 | + | 4 | ( | x | + | 30 | ) |
| = | 24 | x | + | 120 | + | 4 | x | + | 4 | × | 30 |
| = | 24 | x | + | 120 | + | 4 | x | + | 120 |
| = | 28 | x | + | 240 |
| 28 | x | + | 240 | = | 1766 |
| 28 | x | = | 1766 | − | 240 |
| 28 | x | = | 1526 |
| x | = | 1526 | ÷ | 28 |
| = | 1526 | × | 1 28 |
| = | 109 | × | 1 2 |
| x | = | 109 2 |
| x | = | 54.5 |