| ( | 9 10 | x | − | 60 | ) | × | 12 | = | ( | x | − | 60 | ) | × | 10 |
| Left side of the equation = | 9 10 | x | × | 12 | − | 60 | × | 12 |
| = | 54 5 | x | − | 720 |
54 5 | x | − | 720 | = | ( | x | − | 60 | ) | × | 10 |
| Right side of the equation = | x | × | 10 | − | 60 | × | 10 |
| = | x | × | 10 | − | 600 |
54 5 | x | − | 720 | = | 10 | x | − | 600 |
54 5 | x | − | 10 | x | = | - | 600 | + | 720 |
4 5 | x | = | - | 600 | + | 720 |
4 5 | x | = | 120 |
| x | = | 120 | ÷ | 4 5 |
| = | 120 | × | 5 4 |
| = | 30 | × | 5 |
| x | = | 150 |