| ( | 450 | − | 50 | − | x | ) | ÷ | 120 | = | x | ÷ | 80 |
| Left side of the equation = | 450 | × | 1 120 | − | 50 | × | 1 120 | − | x | × | 1 120 |
| = | 15 4 | − | 5 12 | − | x | × | 1 120 |
| = | 10 3 | − | 1 120 | x |
10 3 | − | 1 120 | x | = | x | ÷ | 80 |
| - | 1 120 | x | − | 1 80 | x | = | - | 10 3 |
| - | 1 48 | x | = | - | 10 3 |
10 3 | = | 1 48 | x |
1 48 | x | = | 10 3 |
| x | = | 10 3 | ÷ | 1 48 |
| = | 10 3 | × | 48 |
| = | 10 | × | 16 |
| x | = | 160 |