| ( | 4 | + | 2 | x | ) | ( | 3 | + | 2 | x | ) | = | 30 |
| Left side of the equation = | 4 | ( | 3 | + | 2 | x | ) | + | 2 | x | ( | 3 | + | 2 | x | ) |
| = | 4 | × | 3 | + | 4 | × | 2 | x | + | 2 | x | ( | 3 | + | 2 | x | ) |
| = | 12 | + | 8 | x | + | 2 | x | ( | 3 | + | 2 | x | ) |
| = | 12 | + | 8 | x | + | 2 | x | × | 3 | + | 2 | x | × | 2 | x |
| = | 12 | + | 8 | x | + | 6 | x | + | 4 | x | x |
| = | 12 | + | 14 | x | + | 4 | x | x |
| 12 | + | 14 | x | + | 4 | x | x | = | 30 |
| x1= | - | 9 2 |
| x2=1 |