| 500 | × | 9 10 | + | 4 5 | ( | x | − | 500 | ) | = | 490 |
| Left side of the equation = | 450 | + | 4 5 | ( | x | − | 500 | ) |
| 450 | + | 4 5 | ( | x | − | 500 | ) | = | 490 |
| Left side of the equation = | 450 | + | 4 5 | x | − | 4 5 | × | 500 |
| = | 450 | + | 4 5 | x | − | 400 |
| = | 50 | + | 4 5 | x |
| 50 | + | 4 5 | x | = | 490 |
4 5 | x | = | 490 | − | 50 |
4 5 | x | = | 440 |
| x | = | 440 | ÷ | 4 5 |
| = | 440 | × | 5 4 |
| = | 110 | × | 5 |
| x | = | 550 |