| ( | 1500 | − | 1000 | ) | ÷ | ( | 3000 | − | 1500 | ) | = | ( | A | − | 383 10 | ) | ÷ | ( | 519 5 | − | A | ) |
| Multiply both sides of the equation by: | ( | 3000 | − | 1500 | ) | , | ( | 519 5 | − | A | ) |
| ( | 1500 | − | 1000 | ) | ( | 519 5 | − | A | ) | = | ( | A | − | 383 10 | ) | ( | 3000 | − | 1500 | ) |
| 1500 | ( | 519 5 | − | A | ) | − | 1000 | ( | 519 5 | − | A | ) | = | ( | A | − | 383 10 | ) | ( | 3000 | − | 1500 | ) |
| 1500 | ( | 519 5 | − | A | ) | − | 1000 | ( | 519 5 | − | A | ) | = | A | ( | 3000 | − | 1500 | ) | − | 383 10 | ( | 3000 | − | 1500 | ) |
| 1500 | × | 519 5 | − | 1500 | A | − | 1000 | ( | 519 5 | − | A | ) | = | A | ( | 3000 | − | 1500 | ) | − | 383 10 | ( | 3000 | − | 1500 | ) |
| 1500 | × | 519 5 | − | 1500 | A | − | 1000 | ( | 519 5 | − | A | ) | = | A | × | 3000 | − | A | × | 1500 | − | 383 10 | ( | 3000 | − | 1500 | ) |
| 155700 | − | 1500 | A | − | 1000 | ( | 519 5 | − | A | ) | = | A | × | 3000 | − | A | × | 1500 | − | 383 10 | ( | 3000 | − | 1500 | ) |
| 155700 | − | 1500 | A | − | 1000 | ( | 519 5 | − | A | ) | = | 1500 | A | − | 383 10 | ( | 3000 | − | 1500 | ) |
| 155700 | − | 1500 | A | − | 1000 | × | 519 5 | + | 1000 | A | = | 1500 | A | − | 383 10 | ( | 3000 | − | 1500 | ) |
| 155700 | − | 1500 | A | − | 1000 | × | 519 5 | + | 1000 | A | = | 1500 | A | − | 383 10 | × | 3000 | + | 383 10 | × | 1500 |
| 155700 | − | 1500 | A | − | 103800 | + | 1000 | A | = | 1500 | A | − | 114900 | + | 57450 |
| 51900 | − | 500 | A | = | 1500 | A | − | 57450 |
| - | 500 | A | − | 1500 | A | = | - | 57450 | − | 51900 |
| - | 2000 | A | = | - | 57450 | − | 51900 |
| - | 2000 | A | = | - | 109350 |
| 109350 | = | 2000 | A |
| 2000 | A | = | 109350 |
| A | = | 109350 | ÷ | 2000 |
| = | 109350 | × | 1 2000 |
| = | 2187 | × | 1 40 |
| A | = | 2187 40 |
| A | = | 54.675 |