| 5000 | × | 3 20 | ( | x | + | 7 10 | ) | + | 700 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 30000 | × | 7 10 | = | 16000 | ( | 3 20 | x | + | 3 20 | × | 7 10 | + | 1 | ) |
| 方程左边 = | 750 | ( | x | + | 7 10 | ) | + | 700 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 21000 |
| 750 | ( | x | + | 7 10 | ) | + | 700 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 21000 | = | 16000 | ( | 3 20 | x | + | 3 20 | × | 7 10 | + | 1 | ) |
| 方程左边 = | 750 | x | + | 750 | × | 7 10 | + | 700 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 21000 |
| = | 750 | x | + | 525 | + | 700 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 21000 |
| = | 2350 | x | + | 21525 | + | 700 | ( | 3 10 | − | x | ) |
| = | 2350 | x | + | 21525 | + | 700 | × | 3 10 | − | 700 | x |
| = | 2350 | x | + | 21525 | + | 210 | − | 700 | x |
| = | 1650 | x | + | 21735 |
| 1650 | x | + | 21735 | = | 16000 | ( | 3 20 | x | + | 3 20 | × | 7 10 | + | 1 | ) |
| 方程右边 = | 16000 | × | 3 20 | x | + | 16000 | × | 3 20 | × | 7 10 | + | 16000 | × | 1 |
| = | 2400 | x | + | 1680 | + | 16000 |
| = | 2400 | x | + | 17680 |
| 1650 | x | + | 21735 | = | 2400 | x | + | 17680 |
| 1650 | x | − | 2400 | x | = | 17680 | − | 21735 |
| - | 750 | x | = | 17680 | − | 21735 |
| - | 750 | x | = | - | 4055 |
| 4055 | = | 750 | x |
| 750 | x | = | 4055 |
| x | = | 4055 | ÷ | 750 |
| = | 4055 | × | 1 750 |
| = | 811 | × | 1 150 |
| x | = | 811 150 |
| x | = | 5.406667 |