| ( | 900 | − | 120 | ) | A | − | 12000000 | − | 560 | A | = | 0 |
| Left side of the equation = | 900 | A | − | 120 | A | − | 12000000 | − | 560 | A |
| = | 220 | A | − | 12000000 |
| 220 | A | − | 12000000 | = | 0 |
| 220 | A | = | 0 | + | 12000000 |
| 220 | A | = | 12000000 |
| A | = | 12000000 | ÷ | 220 |
| = | 12000000 | × | 1 220 |
| = | 600000 | × | 1 11 |
| A | = | 600000 11 |
| A | = | 54545.454545 |