| ( | 12 | + | 5 2 | x | + | x | ÷ | 40 | × | 2 5 | × | 60 | ) | − | ( | 14 | + | 12 5 | ( | x | − | 3 | ) | ) | = | 89 5 |
| Left side of the equation = | 12 | + | 5 2 | x | + | x | ÷ | 40 | × | 2 5 | × | 60 | − | ( | 14 | + | 12 5 | ( | x | − | 3 | ) | ) |
| = | 12 | + | 5 2 | x | + | x | × | 3 5 | − | ( | 14 | + | 12 5 | ( | x | − | 3 | ) | ) |
| = | 12 | + | 31 10 | x | − | ( | 14 | + | 12 5 | ( | x | − | 3 | ) | ) |
| = | 12 | + | 31 10 | x | − | 14 | − | 12 5 | ( | x | − | 3 | ) |
| = | - | 2 | + | 31 10 | x | − | 12 5 | ( | x | − | 3 | ) |
| = | - | 2 | + | 31 10 | x | − | 12 5 | x | + | 12 5 | × | 3 |
| = | - | 2 | + | 31 10 | x | − | 12 5 | x | + | 36 5 |
| = | 26 5 | + | 7 10 | x |
26 5 | + | 7 10 | x | = | 89 5 |
7 10 | x | = | 89 5 | − | 26 5 |
7 10 | x | = | 63 5 |
| x | = | 63 5 | ÷ | 7 10 |
| = | 63 5 | × | 10 7 |
| = | 9 | × | 2 |
| x | = | 18 |