| 3 | x | + | 6 | ( | x | − | 25 | ) | = | 3830 | − | 2855 |
| Left side of the equation = | 3 | x | + | 6 | x | − | 6 | × | 25 |
| = | 3 | x | + | 6 | x | − | 150 |
| = | 9 | x | − | 150 |
| 9 | x | − | 150 | = | 3830 | − | 2855 |
| Right side of the equation = | 975 |
| 9 | x | − | 150 | = | 975 |
| 9 | x | = | 975 | + | 150 |
| 9 | x | = | 1125 |
| x | = | 1125 | ÷ | 9 |
| = | 1125 | × | 1 9 |
| = | 125 | × | 1 |
| x | = | 125 |