| 2 | ( | 180 | − | x | ) | = | 5 | ( | 90 | − | x | ) | + | 30 |
| Left side of the equation = | 2 | × | 180 | − | 2 | x |
| = | 360 | − | 2 | x |
| 360 | − | 2 | x | = | 5 | ( | 90 | − | x | ) | + | 30 |
| Right side of the equation = | 5 | × | 90 | − | 5 | x | + | 30 |
| = | 450 | − | 5 | x | + | 30 |
| = | 480 | − | 5 | x |
| 360 | − | 2 | x | = | 480 | − | 5 | x |
| - | 2 | x | + | 5 | x | = | 480 | − | 360 |
| 3 | x | = | 480 | − | 360 |
| 3 | x | = | 120 |
| x | = | 120 | ÷ | 3 |
| = | 120 | × | 1 3 |
| = | 40 | × | 1 |
| x | = | 40 |