| ( | 33 | + | x | ) | ÷ | ( | 45 | + | x | ) | = | 7 10 |
| Multiply both sides of the equation by: | ( | 45 | + | x | ) |
| ( | 33 | + | x | ) | = | 7 10 | ( | 45 | + | x | ) |
| 33 | + | x | = | 7 10 | ( | 45 | + | x | ) |
| 33 | + | x | = | 7 10 | × | 45 | + | 7 10 | x |
| 33 | + | x | = | 63 2 | + | 7 10 | x |
| x | − | 7 10 | x | = | 63 2 | − | 33 |
3 10 | x | = | 63 2 | − | 33 |
3 10 | x | = | - | 3 2 |
| x | = | - | 3 2 | ÷ | 3 10 |
| = | - | 3 2 | × | 10 3 |
| = | - | 1 | × | 5 |
| x | = | - | 5 |