| ( | a | ( | 200 | − | 120 | ) | − | 100 | − | 500 | × | 5 100 | ) | ( | 1 | − | 30 100 | ) | ÷ | 50 | = | 0 |
| Left side of the equation = | a | ( | 200 | − | 120 | ) | ( | 1 | − | 30 100 | ) | × | 1 50 | − | 100 | ( | 1 | − | 30 100 | ) | × | 1 50 | − | 500 | × | 5 100 | ( | 1 | − | 30 100 | ) | × | 1 50 |
| = | a | ( | 200 | − | 120 | ) | ( | 1 | − | 30 100 | ) | × | 1 50 | − | 2 | ( | 1 | − | 30 100 | ) | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | a | × | 200 | ( | 1 | − | 30 100 | ) | × | 1 50 | − | a | × | 120 | ( | 1 | − | 30 100 | ) | × | 1 50 | − | 2 | ( | 1 | − | 30 100 | ) | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | a | × | 4 | ( | 1 | − | 30 100 | ) | − | a | × | 12 5 | ( | 1 | − | 30 100 | ) | − | 2 | ( | 1 | − | 30 100 | ) | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | a | × | 4 | × | 1 | − | a | × | 4 | × | 30 100 | − | a | × | 12 5 | ( | 1 | − | 30 100 | ) | − | 2 | ( | 1 | − | 30 100 | ) | − | 1 2 |
| = | a | × | 4 | − | a | × | 6 5 | − | a | × | 12 5 | ( | 1 | − | 30 100 | ) | − | 2 | ( | 1 | − | 30 100 | ) | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | 14 5 | a | − | a | × | 12 5 | ( | 1 | − | 30 100 | ) | − | 2 | ( | 1 | − | 30 100 | ) | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | 14 5 | a | − | a | × | 12 5 | × | 1 | + | a | × | 12 5 | × | 30 100 | − | 2 | ( | 1 | − | 30 100 | ) | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | 14 5 | a | − | a | × | 12 5 | + | a | × | 18 25 | − | 2 | ( | 1 | − | 30 100 | ) | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | 28 25 | a | − | 2 | ( | 1 | − | 30 100 | ) | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | 28 25 | a | − | 2 | × | 1 | + | 2 | × | 30 100 | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | 28 25 | a | − | 2 | + | 3 5 | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | 28 25 | a | − | 7 5 | − | 1 2 | ( | 1 | − | 30 100 | ) |
| = | 28 25 | a | − | 7 5 | − | 1 2 | × | 1 | + | 1 2 | × | 30 100 |
| = | 28 25 | a | − | 7 5 | − | 1 2 | + | 3 20 |
| = | 28 25 | a | − | 7 4 |
28 25 | a | − | 7 4 | = | 0 |
28 25 | a | = | 0 | + | 7 4 |
28 25 | a | = | 7 4 |
| a | = | 7 4 | ÷ | 28 25 |
| = | 7 4 | × | 25 28 |
| = | 1 4 | × | 25 4 |
| a | = | 25 16 |
| a | = | 1.5625 |