| ( | 68 | − | 66 | ) | ÷ | ( | 66 | − | 40 | ) | = | ( | 85 | − | t | ) | ÷ | ( | t | − | 71 | ) |
| Multiply both sides of the equation by: | ( | 66 | − | 40 | ) | , | ( | t | − | 71 | ) |
| ( | 68 | − | 66 | ) | ( | t | − | 71 | ) | = | ( | 85 | − | t | ) | ( | 66 | − | 40 | ) |
| 68 | ( | t | − | 71 | ) | − | 66 | ( | t | − | 71 | ) | = | ( | 85 | − | t | ) | ( | 66 | − | 40 | ) |
| 68 | ( | t | − | 71 | ) | − | 66 | ( | t | − | 71 | ) | = | 85 | ( | 66 | − | 40 | ) | − | t | ( | 66 | − | 40 | ) |
| 68 | t | − | 68 | × | 71 | − | 66 | ( | t | − | 71 | ) | = | 85 | ( | 66 | − | 40 | ) | − | t | ( | 66 | − | 40 | ) |
| 68 | t | − | 68 | × | 71 | − | 66 | ( | t | − | 71 | ) | = | 85 | × | 66 | − | 85 | × | 40 | − | t | ( | 66 | − | 40 | ) |
| 68 | t | − | 4828 | − | 66 | ( | t | − | 71 | ) | = | 5610 | − | 3400 | − | t | ( | 66 | − | 40 | ) |
| 68 | t | − | 4828 | − | 66 | ( | t | − | 71 | ) | = | 2210 | − | t | ( | 66 | − | 40 | ) |
| 68 | t | − | 4828 | − | 66 | t | + | 66 | × | 71 | = | 2210 | − | t | ( | 66 | − | 40 | ) |
| 68 | t | − | 4828 | − | 66 | t | + | 66 | × | 71 | = | 2210 | − | t | × | 66 | + | t | × | 40 |
| 68 | t | − | 4828 | − | 66 | t | + | 4686 | = | 2210 | − | t | × | 66 | + | t | × | 40 |
| 2 | t | − | 142 | = | 2210 | − | 26 | t |
| 2 | t | + | 26 | t | = | 2210 | + | 142 |
| 28 | t | = | 2210 | + | 142 |
| 28 | t | = | 2352 |
| t | = | 2352 | ÷ | 28 |
| = | 2352 | × | 1 28 |
| = | 84 | × | 1 |
| t | = | 84 |