| 80000 | a | − | 80000 | a | × | 5 100 | − | 360000 | = | 40000 |
| Left side of the equation = | 80000 | a | − | 4000 | a | − | 360000 |
| = | 76000 | a | − | 360000 |
| 76000 | a | − | 360000 | = | 40000 |
| 76000 | a | = | 40000 | + | 360000 |
| 76000 | a | = | 400000 |
| a | = | 400000 | ÷ | 76000 |
| = | 400000 | × | 1 76000 |
| = | 100 | × | 1 19 |
| a | = | 100 19 |
| a | = | 5.263158 |