| 400 | ( | 1 | + | m | ) | × | 24 | + | 500 | × | 24 | ( | 1 | + | 2 | m | ) | ( | 1 | + | m | ) | = | 21600 | ( | 1 | + | 20 | ÷ | 9 | × | m | ) |
| 方程左边 = | 9600 | ( | 1 | + | m | ) | + | 12000 | ( | 1 | + | 2 | m | ) | ( | 1 | + | m | ) |
| 9600 | ( | 1 | + | m | ) | + | 12000 | ( | 1 | + | 2 | m | ) | ( | 1 | + | m | ) | = | 21600 | ( | 1 | + | 20 | ÷ | 9 | × | m | ) |
| 方程左边 = | 9600 | × | 1 | + | 9600 | m | + | 12000 | ( | 1 | + | 2 | m | ) | ( | 1 | + | m | ) |
| = | 9600 | + | 9600 | m | + | 12000 | ( | 1 | + | 2 | m | ) | ( | 1 | + | m | ) |
| = | 9600 | + | 9600 | m | + | 12000 | × | 1 | ( | 1 | + | m | ) | + | 12000 | × | 2 | m | ( | 1 | + | m | ) |
| = | 9600 | + | 9600 | m | + | 12000 | ( | 1 | + | m | ) | + | 24000 | m | ( | 1 | + | m | ) |
| = | 9600 | + | 9600 | m | + | 12000 | × | 1 | + | 12000 | m | + | 24000 | m | ( | 1 | + | m | ) |
| = | 9600 | + | 9600 | m | + | 12000 | + | 12000 | m | + | 24000 | m | ( | 1 | + | m | ) |
| = | 21600 | + | 21600 | m | + | 24000 | m | ( | 1 | + | m | ) |
| = | 21600 | + | 21600 | m | + | 24000 | m | × | 1 | + | 24000 | m | m |
| = | 21600 | + | 21600 | m | + | 24000 | m | + | 24000 | m | m |
| = | 21600 | + | 45600 | m | + | 24000 | m | m |
| 21600 | + | 45600 | m | + | 24000 | m | m | = | 21600 | ( | 1 | + | 20 | ÷ | 9 | × | m | ) |
| 方程右边 = | 21600 | × | 1 | + | 21600 | × | 20 | ÷ | 9 | × | m |
| = | 21600 | + | 48000 | m |
| 21600 | + | 45600 | m | + | 24000 | m | m | = | 21600 | + | 48000 | m |
| m2= | 1 10 |