| ( | 27785 | + | a | ) | ÷ | ( | 45087 | + | a | ) | = | 4 5 |
| Multiply both sides of the equation by: | ( | 45087 | + | a | ) |
| ( | 27785 | + | a | ) | = | 4 5 | ( | 45087 | + | a | ) |
| 27785 | + | a | = | 4 5 | ( | 45087 | + | a | ) |
| 27785 | + | a | = | 4 5 | × | 45087 | + | 4 5 | a |
| 27785 | + | a | = | 180348 5 | + | 4 5 | a |
| a | − | 4 5 | a | = | 180348 5 | − | 27785 |
1 5 | a | = | 180348 5 | − | 27785 |
1 5 | a | = | 41423 5 |
| a | = | 41423 5 | ÷ | 1 5 |
| = | 41423 5 | × | 5 |
| = | 41423 | × | 1 |
| a | = | 41423 |