| ( | 5 | ( | 7 | + | X | ) | + | 1 | × | 2 | ) | ÷ | ( | 9 | + | X | ) | = | 49 10 |
| Multiply both sides of the equation by: | ( | 9 | + | X | ) |
| ( | 5 | ( | 7 | + | X | ) | + | 1 | × | 2 | ) | = | 49 10 | ( | 9 | + | X | ) |
| 5 | ( | 7 | + | X | ) | + | 1 | × | 2 | = | 49 10 | ( | 9 | + | X | ) |
| 5 | ( | 7 | + | X | ) | + | 1 | × | 2 | = | 49 10 | × | 9 | + | 49 10 | X |
| 5 | ( | 7 | + | X | ) | + | 2 | = | 441 10 | + | 49 10 | X |
| 5 | × | 7 | + | 5 | X | + | 2 | = | 441 10 | + | 49 10 | X |
| 35 | + | 5 | X | + | 2 | = | 441 10 | + | 49 10 | X |
| 37 | + | 5 | X | = | 441 10 | + | 49 10 | X |
| 5 | X | − | 49 10 | X | = | 441 10 | − | 37 |
1 10 | X | = | 441 10 | − | 37 |
1 10 | X | = | 71 10 |
| X | = | 71 10 | ÷ | 1 10 |
| = | 71 10 | × | 10 |
| = | 71 | × | 1 |
| X | = | 71 |