| 100 | y | − | ( | 508 | + | 40 | × | 100 | ) | − | ( | 13 100 | y | − | 5 | ) | × | 12 100 | × | 100 | = | 120 |
| Left side of the equation = | 100 | y | − | ( | 508 | + | 40 | × | 100 | ) | − | ( | 13 100 | y | − | 5 | ) | × | 12 |
| 100 | y | − | ( | 508 | + | 40 | × | 100 | ) | − | ( | 13 100 | y | − | 5 | ) | × | 12 | = | 120 |
| Left side of the equation = | 100 | y | − | 508 | − | 40 | × | 100 | − | ( | 13 100 | y | − | 5 | ) | × | 12 |
| = | 100 | y | − | 508 | − | 4000 | − | ( | 13 100 | y | − | 5 | ) | × | 12 |
| = | 100 | y | − | 4508 | − | ( | 13 100 | y | − | 5 | ) | × | 12 |
| = | 100 | y | − | 4508 | − | 13 100 | y | × | 12 | + | 5 | × | 12 |
| = | 100 | y | − | 4508 | − | 39 25 | y | + | 60 |
| = | 2461 25 | y | − | 4448 |
2461 25 | y | − | 4448 | = | 120 |
2461 25 | y | = | 120 | + | 4448 |
2461 25 | y | = | 4568 |
| y | = | 4568 | ÷ | 2461 25 |
| = | 4568 | × | 25 2461 |
| y | = | 114200 2461 |
| y | = | 46.403901 |