| 4 | ( | 255 | − | 15 | t | ) | = | 15 | t | − | 155 |
| Left side of the equation = | 4 | × | 255 | − | 4 | × | 15 | t |
| = | 1020 | − | 60 | t |
| 1020 | − | 60 | t | = | 15 | t | − | 155 |
| - | 60 | t | − | 15 | t | = | - | 155 | − | 1020 |
| - | 75 | t | = | - | 155 | − | 1020 |
| - | 75 | t | = | - | 1175 |
| 1175 | = | 75 | t |
| 75 | t | = | 1175 |
| t | = | 1175 | ÷ | 75 |
| = | 1175 | × | 1 75 |
| = | 47 | × | 1 3 |
| t | = | 47 3 |
| t | = | 15.666667 |