| ( | 3205 | + | 5 | X | ) | ÷ | ( | 649 | + | X | ) | = | 99 20 |
| Multiply both sides of the equation by: | ( | 649 | + | X | ) |
| ( | 3205 | + | 5 | X | ) | = | 99 20 | ( | 649 | + | X | ) |
| 3205 | + | 5 | X | = | 99 20 | ( | 649 | + | X | ) |
| 3205 | + | 5 | X | = | 99 20 | × | 649 | + | 99 20 | X |
| 3205 | + | 5 | X | = | 64251 20 | + | 99 20 | X |
| 5 | X | − | 99 20 | X | = | 64251 20 | − | 3205 |
1 20 | X | = | 64251 20 | − | 3205 |
1 20 | X | = | 151 20 |
| X | = | 151 20 | ÷ | 1 20 |
| = | 151 20 | × | 20 |
| = | 151 | × | 1 |
| X | = | 151 |