| 100 | × | 20 | + | x | × | 70 | = | ( | 100 | + | x | ) | × | 25 |
| Left side of the equation = | 2000 | + | x | × | 70 |
| 2000 | + | 70 | x | = | ( | 100 | + | x | ) | × | 25 |
| Right side of the equation = | 100 | × | 25 | + | x | × | 25 |
| = | 2500 | + | x | × | 25 |
| 2000 | + | 70 | x | = | 2500 | + | 25 | x |
| 70 | x | − | 25 | x | = | 2500 | − | 2000 |
| 45 | x | = | 2500 | − | 2000 |
| 45 | x | = | 500 |
| x | = | 500 | ÷ | 45 |
| = | 500 | × | 1 45 |
| = | 100 | × | 1 9 |
| x | = | 100 9 |
| x | = | 11.111111 |