| 25 | t | ÷ | 2 | − | 80 | = | 3 | ( | 160 | − | 10 | t | ) |
| 方程左边 = | 25 2 | t | − | 80 |
25 2 | t | − | 80 | = | 3 | ( | 160 | − | 10 | t | ) |
| 方程右边 = | 3 | × | 160 | − | 3 | × | 10 | t |
| = | 480 | − | 30 | t |
25 2 | t | − | 80 | = | 480 | − | 30 | t |
25 2 | t | + | 30 | t | = | 480 | + | 80 |
85 2 | t | = | 480 | + | 80 |
85 2 | t | = | 560 |
| t | = | 560 | ÷ | 85 2 |
| = | 560 | × | 2 85 |
| = | 112 | × | 2 17 |
| t | = | 224 17 |
| t | = | 13.176471 |