| 3 | x | + | 1 | ÷ | 3 | × | ( | 20 | − | x | ) | = | 20 |
| Left side of the equation = | 3 | x | + | 1 3 | ( | 20 | − | x | ) |
| 3 | x | + | 1 3 | ( | 20 | − | x | ) | = | 20 |
| Left side of the equation = | 3 | x | + | 1 3 | × | 20 | − | 1 3 | x |
| = | 3 | x | + | 20 3 | − | 1 3 | x |
| = | 8 3 | x | + | 20 3 |
8 3 | x | + | 20 3 | = | 20 |
8 3 | x | = | 20 | − | 20 3 |
8 3 | x | = | 40 3 |
| x | = | 40 3 | ÷ | 8 3 |
| = | 40 3 | × | 3 8 |
| = | 5 | × | 1 |
| x | = | 5 |