( | 10 | + | x | ) | ( | 600 | + | 10 | x | ) | = | 12000 |
Left side of the equation = | 10 | ( | 600 | + | 10 | x | ) | + | x | ( | 600 | + | 10 | x | ) |
= | 10 | × | 600 | + | 10 | × | 10 | x | + | x | ( | 600 | + | 10 | x | ) |
= | 6000 | + | 100 | x | + | x | ( | 600 | + | 10 | x | ) |
= | 6000 | + | 100 | x | + | x | × | 600 | + | x | × | 10 | x |
= | 6000 | + | 700 | x | + | x | × | 10 | x |
6000 | + | 700 | x | + | x | × | 10 | x | = | 12000 |