| 125 | ( | x | − | 1 | ) | × | 3 | + | 216 | = | 0 |
| Left side of the equation = | 375 | ( | x | − | 1 | ) | + | 216 |
| 375 | ( | x | − | 1 | ) | + | 216 | = | 0 |
| Left side of the equation = | 375 | x | − | 375 | × | 1 | + | 216 |
| = | 375 | x | − | 375 | + | 216 |
| = | 375 | x | − | 159 |
| 375 | x | − | 159 | = | 0 |
| 375 | x | = | 0 | + | 159 |
| 375 | x | = | 159 |
| x | = | 159 | ÷ | 375 |
| = | 159 | × | 1 375 |
| = | 53 | × | 1 125 |
| x | = | 53 125 |
| x | = | 0.424 |