| 75 | ( | 16 | − | 4 | t | ) | = | 80 | ( | 12 | − | 3 | t | ) |
| Left side of the equation = | 75 | × | 16 | − | 75 | × | 4 | t |
| = | 1200 | − | 300 | t |
| 1200 | − | 300 | t | = | 80 | ( | 12 | − | 3 | t | ) |
| Right side of the equation = | 80 | × | 12 | − | 80 | × | 3 | t |
| = | 960 | − | 240 | t |
| 1200 | − | 300 | t | = | 960 | − | 240 | t |
| - | 300 | t | + | 240 | t | = | 960 | − | 1200 |
| - | 60 | t | = | 960 | − | 1200 |
| - | 60 | t | = | - | 240 |
| 240 | = | 60 | t |
| 60 | t | = | 240 |
| t | = | 240 | ÷ | 60 |
| = | 240 | × | 1 60 |
| = | 4 | × | 1 |
| t | = | 4 |