100 | a | + | 120 | ( | 300 | − | a | ) | = | 33000 |
Left side of the equation = | 100 | a | + | 120 | × | 300 | − | 120 | a |
= | 100 | a | + | 36000 | − | 120 | a |
= | - | 20 | a | + | 36000 |
- | 20 | a | + | 36000 | = | 33000 |
- | 20 | a | = | 33000 | − | 36000 |
- | 20 | a | = | - | 3000 |
3000 | = | 20 | a |
20 | a | = | 3000 |
a | = | 3000 | ÷ | 20 |
= | 3000 | × | 1 20 |
= | 150 | × | 1 |
a | = | 150 |