| 9 | ÷ | 10 | × | x | = | 4 | ÷ | 5 | × | ( | x | + | 5 | ) |
| Left side of the equation = | 9 10 | x |
9 10 | x | = | 4 | ÷ | 5 | × | ( | x | + | 5 | ) |
| Right side of the equation = | 4 5 | ( | x | + | 5 | ) |
9 10 | x | = | 4 5 | ( | x | + | 5 | ) |
| Right side of the equation = | 4 5 | x | + | 4 5 | × | 5 |
| = | 4 5 | x | + | 4 |
9 10 | x | = | 4 5 | x | + | 4 |
9 10 | x | − | 4 5 | x | = | 4 |
1 10 | x | = | 4 |
| x | = | 4 | ÷ | 1 10 |
| = | 4 | × | 10 |
| x | = | 40 |