Odpowiedź :
a)
6x + 4 = 2x
6x - 2x = -4
4x = -4 | : 4
x = -1
b)
3x - 4 = 5x
3x - 5x = 4
-2x = 4 | : (-2)
x = -2
c)
-2x + 7 = 6x - 9
-2x - 6x = -9 - 7
-8x = -16 | : (-8)
x = 2
d)
-2x = 7x + 18
-2x - 7x = 18
-9x = 18 | : (-9)
x = -2
e)
-4x + 5 = 25 - 9x
-4x + 9x = 25 - 5
5x = 20 | : 5
x = 4