Tìm x biết: a) (x + 1).(x - 2) < 0; b) (x - 2).(x + 2/3) > 0

Tìm x
a) (x+1).(x-2)<0
b) (x-2).(x+2/3)>0
c) 3x.(x-2)=0
d) (2x-1).(x+3)<0
e) (3-4x).(2x+1)>0