( | 700 | − | 10 | x | ) | ( | x | − | 40 | ) | = | 2000 |
Left side of the equation = | 700 | ( | x | − | 40 | ) | − | 10 | x | ( | x | − | 40 | ) |
= | 700 | x | − | 700 | × | 40 | − | 10 | x | ( | x | − | 40 | ) |
= | 700 | x | − | 28000 | − | 10 | x | ( | x | − | 40 | ) |
= | 700 | x | − | 28000 | − | 10 | x | x | + | 10 | x | × | 40 |
= | 700 | x | − | 28000 | − | 10 | x | x | + | 400 | x |
= | 1100 | x | − | 28000 | − | 10 | x | x |
1100 | x | − | 28000 | − | 10 | x | x | = | 2000 |