| ( | 50000 | ( | 1 | + | 15 200 | ) | + | y | ) | × | 12 100 | = | 50000 | × | 15 200 | + | 2000 |
| 方程左边 = | 50000 | ( | 1 | + | 15 200 | ) | × | 12 100 | + | y | × | 12 100 |
| = | 6000 | ( | 1 | + | 15 200 | ) | + | y | × | 12 100 |
| = | 6000 | × | 1 | + | 6000 | × | 15 200 | + | 12 100 | y |
| = | 6000 | + | 450 | + | 12 100 | y |
| = | 6450 | + | 12 100 | y |
| 6450 | + | 12 100 | y | = | 50000 | × | 15 200 | + | 2000 |
| 方程右边 = | 3750 | + | 2000 |
| = | 5750 |
| 6450 | + | 12 100 | y | = | 5750 |
12 100 | y | = | 5750 | − | 6450 |
12 100 | y | = | - | 700 |
| y | = | - | 700 | ÷ | 12 100 |
| = | - | 700 | × | 100 12 |
| = | - | 175 | × | 100 3 |
| y | = | - | 17500 3 |
| y | = | - 5833.333333 |