| 11 | ( | t | − | 56 | ) | = | 17 | ( | 80 | − | t | ) |
| 方程左边 = | 11 | t | − | 11 | × | 56 |
| = | 11 | t | − | 616 |
| 11 | t | − | 616 | = | 17 | ( | 80 | − | t | ) |
| 方程右边 = | 17 | × | 80 | − | 17 | t |
| = | 1360 | − | 17 | t |
| 11 | t | − | 616 | = | 1360 | − | 17 | t |
| 11 | t | + | 17 | t | = | 1360 | + | 616 |
| 28 | t | = | 1360 | + | 616 |
| 28 | t | = | 1976 |
| t | = | 1976 | ÷ | 28 |
| = | 1976 | × | 1 28 |
| = | 494 | × | 1 7 |
| t | = | 494 7 |
| t | = | 70.571429 |