| ( | 1000 | − | 200 | m | ) | ( | 1 | + | 1 2 | m | ) | + | 500 | ( | 1 | + | m | ) | = | 14400 |
| 方程左边 = | 1000 | ( | 1 | + | 1 2 | m | ) | − | 200 | m | ( | 1 | + | 1 2 | m | ) | + | 500 | ( | 1 | + | m | ) |
| = | 1000 | × | 1 | + | 1000 | × | 1 2 | m | − | 200 | m | ( | 1 | + | 1 2 | m | ) | + | 500 | ( | 1 | + | m | ) |
| = | 1000 | + | 500 | m | − | 200 | m | ( | 1 | + | 1 2 | m | ) | + | 500 | ( | 1 | + | m | ) |
| = | 1000 | + | 500 | m | − | 200 | m | × | 1 | − | 200 | m | × | 1 2 | m | + | 500 | ( | 1 | + | m | ) |
| = | 1000 | + | 500 | m | − | 200 | m | − | 100 | m | m | + | 500 | ( | 1 | + | m | ) |
| = | 1000 | + | 300 | m | − | 100 | m | m | + | 500 | ( | 1 | + | m | ) |
| = | 1000 | + | 300 | m | − | 100 | m | m | + | 500 | × | 1 | + | 500 | m |
| = | 1000 | + | 300 | m | − | 100 | m | m | + | 500 | + | 500 | m |
| = | 1500 | + | 800 | m | − | 100 | m | m |
| 1500 | + | 800 | m | − | 100 | m | m | = | 14400 |