| ( | ( | 20 | − | 2 | x | ) | x | + | ( | 30 | − | 2 | x | ) | x | ) | × | 2 | = | 200 |
| Left side of the equation = | ( | 20 | − | 2 | x | ) | x | × | 2 | + | ( | 30 | − | 2 | x | ) | x | × | 2 |
| = | 20 | x | × | 2 | − | 2 | x | x | × | 2 | + | ( | 30 | − | 2 | x | ) | x | × | 2 |
| = | 40 | x | − | 4 | x | x | + | ( | 30 | − | 2 | x | ) | x | × | 2 |
| = | 40 | x | − | 4 | x | x | + | 30 | x | × | 2 | − | 2 | x | x | × | 2 |
| = | 40 | x | − | 4 | x | x | + | 60 | x | − | 4 | x | x |
| = | 100 | x | − | 4 | x | x | − | 4 | x | x |
| 100 | x | − | 4 | x | x | − | 4 | x | x | = | 200 |
| x1= | 5 2 |
| x2=10 |