( | 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 |
= | 300 | x | + | 28000 | − | 10 | x | x |
300 | x | + | 28000 | − | 10 | x | x | = | 2000 |