a) (x-2)/3 - 3x = 2 │*3
x-2-9x = 6
x-9x = 6+2
-8x = 8
x = -1
b) 3x-5(2x+1) = 3(3-2x)
3x-10x-5 = 9-6x
-7x+6x = 9+5
-x = 14
x = -14