Odpowiedź :
Zadanie
4x + 7 = 31 l -7
4x = 24 l :4
x = 6
2x - 5 = 13 l +5
2x = 18 l :2
x = 9
3x - 5= 16 l +5
3x = 21 l :3
x = 7
5x - 3 = 12 l +3
5x = 15 l :5
x = 3
Zadanie
4x + 7 = 31 l -7
4x = 24 l :4
x = 6
2x - 5 = 13 l +5
2x = 18 l :2
x = 9
3x - 5= 16 l +5
3x = 21 l :3
x = 7
5x - 3 = 12 l +3
5x = 15 l :5
x = 3