| x | + | 5 4 | ( | 7 50 | − | x | ) | = | 3 20 |
| Left side of the equation = | x | + | 5 4 | × | 7 50 | − | 5 4 | x |
| = | x | + | 7 40 | − | 5 4 | x |
| = | - | 1 4 | x | + | 7 40 |
| - | 1 4 | x | + | 7 40 | = | 3 20 |
| - | 1 4 | x | = | 3 20 | − | 7 40 |
| - | 1 4 | x | = | - | 1 40 |
1 40 | = | 1 4 | x |
1 4 | x | = | 1 40 |
| x | = | 1 40 | ÷ | 1 4 |
| = | 1 40 | × | 4 |
| = | 1 10 | × | 1 |
| x | = | 1 10 |
| x | = | 0.1 |