| ( | ( | ( | 2900 | − | y | ) | ÷ | 50 | ) | × | 4 | + | 8 | ) | ( | y | − | 2500 | ) | = | 5000 |
| 方程左边 = | ( | ( | 2900 | − | y | ) | ÷ | 50 | ) | × | 4 | ( | y | − | 2500 | ) | + | 8 | ( | y | − | 2500 | ) |
| = | ( | 2900 | − | y | ) | ÷ | 50 | × | 4 | ( | y | − | 2500 | ) | + | 8 | ( | y | − | 2500 | ) |
| = | ( | 2900 | − | y | ) | × | 2 25 | ( | y | − | 2500 | ) | + | 8 | ( | y | − | 2500 | ) |
| = | 2900 | × | 2 25 | ( | y | − | 2500 | ) | − | y | × | 2 25 | ( | y | − | 2500 | ) | + | 8 | ( | y | − | 2500 | ) |
| = | 232 | ( | y | − | 2500 | ) | − | y | × | 2 25 | ( | y | − | 2500 | ) | + | 8 | ( | y | − | 2500 | ) |
| = | 232 | y | − | 232 | × | 2500 | − | y | × | 2 25 | ( | y | − | 2500 | ) | + | 8 | ( | y | − | 2500 | ) |
| = | 232 | y | − | 580000 | − | y | × | 2 25 | ( | y | − | 2500 | ) | + | 8 | ( | y | − | 2500 | ) |
| = | 232 | y | − | 580000 | − | y | × | 2 25 | y | + | y | × | 2 25 | × | 2500 | + | 8 | ( | y | − | 2500 | ) |
| = | 232 | y | − | 580000 | − | y | × | 2 25 | y | + | y | × | 200 | + | 8 | ( | y | − | 2500 | ) |
| = | 432 | y | − | 580000 | − | y | × | 2 25 | y | + | 8 | ( | y | − | 2500 | ) |
| = | 432 | y | − | 580000 | − | y | × | 2 25 | y | + | 8 | y | − | 8 | × | 2500 |
| = | 432 | y | − | 580000 | − | y | × | 2 25 | y | + | 8 | y | − | 20000 |
| = | 440 | y | − | 600000 | − | y | × | 2 25 | y |
| 440 | y | − | 600000 | − | y | × | 2 25 | y | = | 5000 |