| 20 | x | + | ( | ( | x | ÷ | 3 | ) | × | 2 | ) | × | 30 | × | 3 | = | 1769 10 |
| 方程左边 = | 20 | x | + | ( | ( | x | ÷ | 3 | ) | × | 2 | ) | × | 90 |
| 20 | x | + | ( | ( | x | ÷ | 3 | ) | × | 2 | ) | × | 90 | = | 1769 10 |
| 方程左边 = | 20 | x | + | ( | x | ÷ | 3 | ) | × | 2 | × | 90 |
| = | 20 | x | + | ( | x | ÷ | 3 | ) | × | 180 |
| = | 20 | x | + | x | ÷ | 3 | × | 180 |
| = | 20 | x | + | x | × | 60 |
| = | 80 | x |
| 80 | x | = | 1769 10 |
| x | = | 1769 10 | ÷ | 80 |
| = | 1769 10 | × | 1 80 |
| x | = | 1769 800 |
| x | = | 2.21125 |