2 5 | a | + | 2 5 | × | 7 10 | ( | 84 | − | a | ) | = | 768 25 |
| Left side of the equation = | 2 5 | a | + | 7 25 | ( | 84 | − | a | ) |
2 5 | a | + | 7 25 | ( | 84 | − | a | ) | = | 768 25 |
| Left side of the equation = | 2 5 | a | + | 7 25 | × | 84 | − | 7 25 | a |
| = | 2 5 | a | + | 588 25 | − | 7 25 | a |
| = | 3 25 | a | + | 588 25 |
3 25 | a | + | 588 25 | = | 768 25 |
3 25 | a | = | 768 25 | − | 588 25 |
3 25 | a | = | 36 5 |
| a | = | 36 5 | ÷ | 3 25 |
| = | 36 5 | × | 25 3 |
| = | 12 | × | 5 |
| a | = | 60 |