( | 15 | − | a | ) | ( | 4 | a | + | 256 | ) | = | 4200 |
Left side of the equation = | 15 | ( | 4 | a | + | 256 | ) | − | a | ( | 4 | a | + | 256 | ) |
= | 15 | × | 4 | a | + | 15 | × | 256 | − | a | ( | 4 | a | + | 256 | ) |
= | 60 | a | + | 3840 | − | a | ( | 4 | a | + | 256 | ) |
= | 60 | a | + | 3840 | − | a | × | 4 | a | − | a | × | 256 |
= | - | 196 | a | + | 3840 | − | a | × | 4 | a |
- | 196 | a | + | 3840 | − | a | × | 4 | a | = | 4200 |