| ( | 199 | + | x | ) | ÷ | ( | 258 | + | x | ) | = | 4 5 |
| Multiply both sides of the equation by: | ( | 258 | + | x | ) |
| ( | 199 | + | x | ) | = | 4 5 | ( | 258 | + | x | ) |
| 199 | + | x | = | 4 5 | ( | 258 | + | x | ) |
| 199 | + | x | = | 4 5 | × | 258 | + | 4 5 | x |
| 199 | + | x | = | 1032 5 | + | 4 5 | x |
| x | − | 4 5 | x | = | 1032 5 | − | 199 |
1 5 | x | = | 1032 5 | − | 199 |
1 5 | x | = | 37 5 |
| x | = | 37 5 | ÷ | 1 5 |
| = | 37 5 | × | 5 |
| = | 37 | × | 1 |
| x | = | 37 |