( | 10 | + | a | ) | ( | 600 | − | 10 | a | ) | = | 10000 |
Left side of the equation = | 10 | ( | 600 | − | 10 | a | ) | + | a | ( | 600 | − | 10 | a | ) |
= | 10 | × | 600 | − | 10 | × | 10 | a | + | a | ( | 600 | − | 10 | a | ) |
= | 6000 | − | 100 | a | + | a | ( | 600 | − | 10 | a | ) |
= | 6000 | − | 100 | a | + | a | × | 600 | − | a | × | 10 | a |
= | 6000 | + | 500 | a | − | a | × | 10 | a |
6000 | + | 500 | a | − | a | × | 10 | a | = | 10000 |