| ( | 500 | + | 100 | m | ) | ( | 2 | − | m | ) | + | 3600 | = | 1700 |
| 方程左边 = | 500 | ( | 2 | − | m | ) | + | 100 | m | ( | 2 | − | m | ) | + | 3600 |
| = | 500 | × | 2 | − | 500 | m | + | 100 | m | ( | 2 | − | m | ) | + | 3600 |
| = | 1000 | − | 500 | m | + | 100 | m | ( | 2 | − | m | ) | + | 3600 |
| = | 4600 | − | 500 | m | + | 100 | m | ( | 2 | − | m | ) |
| = | 4600 | − | 500 | m | + | 100 | m | × | 2 | − | 100 | m | m |
| = | 4600 | − | 500 | m | + | 200 | m | − | 100 | m | m |
| = | 4600 | − | 300 | m | − | 100 | m | m |
| 4600 | − | 300 | m | − | 100 | m | m | = | 1700 |