( | 280 | − | x | ) | ( | 76 | + | 5 | x | ) | = | 0 |
Left side of the equation = | 280 | ( | 76 | + | 5 | x | ) | − | x | ( | 76 | + | 5 | x | ) |
= | 280 | × | 76 | + | 280 | × | 5 | x | − | x | ( | 76 | + | 5 | x | ) |
= | 21280 | + | 1400 | x | − | x | ( | 76 | + | 5 | x | ) |
= | 21280 | + | 1400 | x | − | x | × | 76 | − | x | × | 5 | x |
= | 21280 | + | 1324 | x | − | x | × | 5 | x |
21280 | + | 1324 | x | − | x | × | 5 | x | = | 0 |
x= | - | 76 5 |