I Jeszce
8x-9=1
40-6x=28
szybko!!!!

6x + 12 = 42 | -12
6x = 30 | : 6
x = 5
-3x + 13 = 7 | -13
-3x = -6 | : (-3)
x = 2
9 + 2x = 31 | -9
2x = 22 | : 2
x = 11
-19 + 4x = -23 | +19
4x = -4 | : 4
x = -1
8x - 9 = 1 | +9
8x = 10 | :8
x = 1,25
40 - 6x = 28 | -40
-6x = -12 | : (-6)
x = 2