( | 1 | − | x | ) | ( | 10 | − | 7 | x | + | x | x | − | 4 | ) | = | 0 |
Left side of the equation = | 1 | ( | 10 | − | 7 | x | + | x | x | − | 4 | ) | − | x | ( | 10 | − | 7 | x | + | x | x | − | 4 | ) |
= | 1 | × | 10 | − | 1 | × | 7 | x | + | 1 | x | x | − | 1 | × | 4 | − | x | ( | 10 | − | 7 | x | + | x | x | − | 4 | ) |
= | 10 | − | 7 | x | + | 1 | x | x | − | 4 | − | x | ( | 10 | − | 7 | x | + | x | x | − | 4 | ) |
= | 6 | − | 7 | x | + | 1 | x | x | − | x | ( | 10 | − | 7 | x | + | x | x | − | 4 | ) |
= | 6 | − | 7 | x | + | 1 | x | x | − | x | × | 10 | + | x | × | 7 | x | − | x |
= | 6 | − | 13 | x | + | 1 | x | x | + | x | × | 7 | x | − | x | x | x |
6 | − | 13 | x | + | 1 | x | x | + | x | × | 7 | x | − | x | x | x | = | 0 |