| ( | 78 | − | x | ) | ÷ | x | = | 921 1000 |
| Multiply both sides of the equation by: | x |
| ( | 78 | − | x | ) | = | 921 1000 | x |
| 78 | − | x | = | 921 1000 | x |
| - | x | − | 921 1000 | x | = | - | 78 |
| - | 1921 1000 | x | = | - | 78 |
| 78 | = | 1921 1000 | x |
1921 1000 | x | = | 78 |
| x | = | 78 | ÷ | 1921 1000 |
| = | 78 | × | 1000 1921 |
| x | = | 78000 1921 |
| x | = | 40.603852 |