| 125 | ÷ | 12 | × | ( | 4 | x | + | 5 | x | + | 12 | ) | = | 500 |
| Left side of the equation = | 125 12 | ( | 4 | x | + | 5 | x | + | 12 | ) |
125 12 | ( | 4 | x | + | 5 | x | + | 12 | ) | = | 500 |
| Left side of the equation = | 125 12 | × | 4 | x | + | 125 12 | × | 5 | x | + | 125 12 | × | 12 |
| = | 125 3 | x | + | 625 12 | x | + | 125 |
| = | 375 4 | x | + | 125 |
375 4 | x | + | 125 | = | 500 |
375 4 | x | = | 500 | − | 125 |
375 4 | x | = | 375 |
| x | = | 375 | ÷ | 375 4 |
| = | 375 | × | 4 375 |
| = | 1 | × | 4 |
| x | = | 4 |