| ( | 3 | + | 5 | ) | ( | 9 | + | x | ) | = | ( | 4 | + | 6 | ) | x |
| Left side of the equation = | 3 | ( | 9 | + | x | ) | + | 5 | ( | 9 | + | x | ) |
| = | 3 | × | 9 | + | 3 | x | + | 5 | ( | 9 | + | x | ) |
| = | 27 | + | 3 | x | + | 5 | ( | 9 | + | x | ) |
| = | 27 | + | 3 | x | + | 5 | × | 9 | + | 5 | x |
| = | 27 | + | 3 | x | + | 45 | + | 5 | x |
| = | 72 | + | 8 | x |
| 72 | + | 8 | x | = | ( | 4 | + | 6 | ) | x |
| Right side of the equation = | 4 | x | + | 6 | x |
| = | 10 | x |
| 72 | + | 8 | x | = | 10 | x |
| 8 | x | − | 10 | x | = | - | 72 |
| - | 2 | x | = | - | 72 |
| 72 | = | 2 | x |
| 2 | x | = | 72 |
| x | = | 72 | ÷ | 2 |
| = | 72 | × | 1 2 |
| = | 36 | × | 1 |
| x | = | 36 |