| ( | 7 | x | − | 1 | ) | ( | 3 | x | − | 8 | ) | = | 0 |
| Left side of the equation = | 7 | x | ( | 3 | x | − | 8 | ) | − | 1 | ( | 3 | x | − | 8 | ) |
| = | 7 | x | × | 3 | x | − | 7 | x | × | 8 | − | 1 | ( | 3 | x | − | 8 | ) |
| = | 21 | x | x | − | 56 | x | − | 1 | ( | 3 | x | − | 8 | ) |
| = | 21 | x | x | − | 56 | x | − | 1 | × | 3 | x | + | 1 | × | 8 |
| = | 21 | x | x | − | 56 | x | − | 3 | x | + | 8 |
| = | 21 | x | x | − | 59 | x | + | 8 |
| 21 | x | x | − | 59 | x | + | 8 | = | 0 |
| x1= | 1 7 |
| x2= | 8 3 |