Odpowiedź:
a) 4x - 3 + 5x = 15
4x- 5x = 15 +3
1x = 18
b) 5x + 7 - 3x = 13
5x - 3x = 13 - 7
2x = 6
x= 3
c) 7x - 2 - 6x = 5
7x - 6x = 5 +2
1x = 7
d) 6x - 4 + 4x = 56
6x + 4x = 56 + 4
10 x = 60
x = 6
