| 20 | + | 2 5 | x | − | 40 | = | 30 | + | 5 | x | − | 75 | + | 4 |
| Left side of the equation = | - | 20 | + | 2 5 | x |
| - | 20 | + | 2 5 | x | = | 30 | + | 5 | x | − | 75 | + | 4 |
| Right side of the equation = | - | 41 | + | 5 | x |
| - | 20 | + | 2 5 | x | = | - | 41 | + | 5 | x |
2 5 | x | − | 5 | x | = | - | 41 | + | 20 |
| - | 23 5 | x | = | - | 41 | + | 20 |
| - | 23 5 | x | = | - | 21 |
| 21 | = | 23 5 | x |
23 5 | x | = | 21 |
| x | = | 21 | ÷ | 23 5 |
| = | 21 | × | 5 23 |
| x | = | 105 23 |
| x | = | 4.565217 |