( | 18 | − | x | ) | ( | 300 | + | 30 | x | ) | = | 5850 |
Left side of the equation = | 18 | ( | 300 | + | 30 | x | ) | − | x | ( | 300 | + | 30 | x | ) |
= | 18 | × | 300 | + | 18 | × | 30 | x | − | x | ( | 300 | + | 30 | x | ) |
= | 5400 | + | 540 | x | − | x | ( | 300 | + | 30 | x | ) |
= | 5400 | + | 540 | x | − | x | × | 300 | − | x | × | 30 | x |
= | 5400 | + | 240 | x | − | x | × | 30 | x |
5400 | + | 240 | x | − | x | × | 30 | x | = | 5850 |