| ( | 20 | + | 2 | x | ) | ( | 15 | + | 2 | x | ) | − | 15 | × | 20 | = | 246 |
| Left side of the equation = | ( | 20 | + | 2 | x | ) | ( | 15 | + | 2 | x | ) | − | 300 |
| ( | 20 | + | 2 | x | ) | ( | 15 | + | 2 | x | ) | − | 300 | = | 246 |
| Left side of the equation = | 20 | ( | 15 | + | 2 | x | ) | + | 2 | x | ( | 15 | + | 2 | x | ) | − | 300 |
| = | 20 | × | 15 | + | 20 | × | 2 | x | + | 2 | x | ( | 15 | + | 2 | x | ) | − | 300 |
| = | 300 | + | 40 | x | + | 2 | x | ( | 15 | + | 2 | x | ) | − | 300 |
| = | 0 | + | 40 | x | + | 2 | x | ( | 15 | + | 2 | x | ) |
| = | 0 | + | 40 | x | + | 2 | x | × | 15 | + | 2 | x | × | 2 | x |
| = | 0 | + | 40 | x | + | 30 | x | + | 4 | x | x |
| = | 0 | + | 70 | x | + | 4 | x | x |
| 0 | + | 70 | x | + | 4 | x | x | = | 246 |
| x1= | - | 41 2 |
| x2=3 |