| ( | x | − | 165 | ) | × | 12 | = | 1500 | + | 250 | × | 12 |
| Left side of the equation = | x | × | 12 | − | 165 | × | 12 |
| = | x | × | 12 | − | 1980 |
| 12 | x | − | 1980 | = | 1500 | + | 250 | × | 12 |
| Right side of the equation = | 1500 | + | 3000 |
| = | 4500 |
| 12 | x | − | 1980 | = | 4500 |
| 12 | x | = | 4500 | + | 1980 |
| 12 | x | = | 6480 |
| x | = | 6480 | ÷ | 12 |
| = | 6480 | × | 1 12 |
| = | 540 | × | 1 |
| x | = | 540 |