| ( | 1 | + | 9 20 | x | ) | ( | 1 | − | 1 10 | x | ) | = | 0 |
| Left side of the equation = | 1 | ( | 1 | − | 1 10 | x | ) | + | 9 20 | x | ( | 1 | − | 1 10 | x | ) |
| = | 1 | × | 1 | − | 1 | × | 1 10 | x | + | 9 20 | x | ( | 1 | − | 1 10 | x | ) |
| = | 1 | − | 1 10 | x | + | 9 20 | x | ( | 1 | − | 1 10 | x | ) |
| = | 1 | − | 1 10 | x | + | 9 20 | x | × | 1 | − | 9 20 | x | × | 1 10 | x |
| = | 1 | − | 1 10 | x | + | 9 20 | x | − | 9 200 | x | x |
| = | 1 | + | 7 20 | x | − | 9 200 | x | x |
| 1 | + | 7 20 | x | − | 9 200 | x | x | = | 0 |
| x1= | - | 20 9 |
| x2=10 |