( | 32 | − | 4 | x | ) | ( | 20 | − | 6 | x | ) | = | 480 |
Left side of the equation = | 32 | ( | 20 | − | 6 | x | ) | − | 4 | x | ( | 20 | − | 6 | x | ) |
= | 32 | × | 20 | − | 32 | × | 6 | x | − | 4 | x | ( | 20 | − | 6 | x | ) |
= | 640 | − | 192 | x | − | 4 | x | ( | 20 | − | 6 | x | ) |
= | 640 | − | 192 | x | − | 4 | x | × | 20 | + | 4 | x | × | 6 | x |
= | 640 | − | 192 | x | − | 80 | x | + | 24 | x | x |
= | 640 | − | 272 | x | + | 24 | x | x |
640 | − | 272 | x | + | 24 | x | x | = | 480 |