4 | x | + | 3 | ( | x | − | 20 | ) | = | 8 | x | − | 7 | ( | 20 | − | x | ) |
Left side of the equation = | 4 | x | + | 3 | x | − | 3 | × | 20 |
= | 4 | x | + | 3 | x | − | 60 |
= | 7 | x | − | 60 |
7 | x | − | 60 | = | 8 | x | − | 7 | ( | 20 | − | x | ) |
Right side of the equation = | 8 | x | − | 7 | × | 20 | + | 7 | x |
= | 8 | x | − | 140 | + | 7 | x |
= | 15 | x | − | 140 |
7 | x | − | 60 | = | 15 | x | − | 140 |
7 | x | − | 15 | x | = | - | 140 | + | 60 |
- | 8 | x | = | - | 140 | + | 60 |
- | 8 | x | = | - | 80 |
80 | = | 8 | x |
8 | x | = | 80 |
x | = | 80 | ÷ | 8 |
= | 80 | × | 1 8 |
= | 10 | × | 1 |
x | = | 10 |