( | 70 | − | x | ) | ( | - | 2 | x | + | 240 | ) | = | 1200 |
Left side of the equation = | 70 | ( | - | 2 | x | + | 240 | ) | − | x | ( | - | 2 | x | + | 240 | ) |
= | - | 70 | × | 2 | x | + | 70 | × | 240 | − | x | ( | - | 2 | x | + | 240 | ) |
= | - | 140 | x | + | 16800 | − | x | ( | - | 2 | x | + | 240 | ) |
= | - | 140 | x | + | 16800 | + | x | × | 2 | x | − | x | × | 240 |
= | - | 380 | x | + | 16800 | + | x | × | 2 | x |
- | 380 | x | + | 16800 | + | x | × | 2 | x | = | 1200 |