| 8 | ( | t | − | 56 | ) | = | 20 | ( | 80 | − | t | ) |
| 方程左边 = | 8 | t | − | 8 | × | 56 |
| = | 8 | t | − | 448 |
| 8 | t | − | 448 | = | 20 | ( | 80 | − | t | ) |
| 方程右边 = | 20 | × | 80 | − | 20 | t |
| = | 1600 | − | 20 | t |
| 8 | t | − | 448 | = | 1600 | − | 20 | t |
| 8 | t | + | 20 | t | = | 1600 | + | 448 |
| 28 | t | = | 1600 | + | 448 |
| 28 | t | = | 2048 |
| t | = | 2048 | ÷ | 28 |
| = | 2048 | × | 1 28 |
| = | 512 | × | 1 7 |
| t | = | 512 7 |
| t | = | 73.142857 |