| x | + | 2 | x | + | ( | 2 | x | + | 20 | ) | ÷ | 4 | = | 180 |
| Left side of the equation = | 3 | x | + | ( | 2 | x | + | 20 | ) | × | 1 4 |
| 3 | x | + | ( | 2 | x | + | 20 | ) | × | 1 4 | = | 180 |
| Left side of the equation = | 3 | x | + | 2 | x | × | 1 4 | + | 20 | × | 1 4 |
| = | 3 | x | + | 1 2 | x | + | 5 |
| = | 7 2 | x | + | 5 |
7 2 | x | + | 5 | = | 180 |
7 2 | x | = | 180 | − | 5 |
7 2 | x | = | 175 |
| x | = | 175 | ÷ | 7 2 |
| = | 175 | × | 2 7 |
| = | 25 | × | 2 |
| x | = | 50 |