| 300 | ÷ | x | = | 100 | ÷ | x | + | 5 | × | 4 |
| Multiply both sides of the equation by: | x |
| 300 | = | 100 | ÷ | 1 | × | 1 | + | 5 | × | 4 | x |
| - | 5 | × | 4 | x | = | 100 | ÷ | 1 | × | 1 | − | 300 |
| - | 20 | x | = | 100 | ÷ | 1 | × | 1 | − | 300 |
| - | 20 | x | = | 100 | − | 300 |
| - | 20 | x | = | - | 200 |
| 200 | = | 20 | x |
| 20 | x | = | 200 |
| x | = | 200 | ÷ | 20 |
| = | 200 | × | 1 20 |
| = | 10 | × | 1 |
| x | = | 10 |