Răspuns :
5 a - 5 b - x = 10
5 ( a - b ) - x = 10
5 × 4 - x = 10
20 - x = 10
x = 20 - 10
x = 10
5 a - 5 b - x = 10
5 ( a - b ) - x = 10
5 × 4 - x = 10
20 - x = 10
- x = 10 - 20
- x = - 10
x = 10
5 a - 5 b - x = 10
5 ( a - b ) - x = 10
5 × 4 - x = 10
20 - x = 10
x = 20 - 10
x = 10
5 a - 5 b - x = 10
5 ( a - b ) - x = 10
5 × 4 - x = 10
20 - x = 10
- x = 10 - 20
- x = - 10
x = 10