| 7 | × | 85 | + | 7 | t | = | 71 | × | 8 | − | 8 | t |
| Left side of the equation = | 595 | + | 7 | t |
| 595 | + | 7 | t | = | 71 | × | 8 | − | 8 | t |
| Right side of the equation = | 568 | − | 8 | t |
| 595 | + | 7 | t | = | 568 | − | 8 | t |
| 7 | t | + | 8 | t | = | 568 | − | 595 |
| 15 | t | = | 568 | − | 595 |
| 15 | t | = | - | 27 |
| t | = | - | 27 | ÷ | 15 |
| = | - | 27 | × | 1 15 |
| = | - | 9 | × | 1 5 |
| t | = | - | 9 5 |
| t | = | - 1.8 |