Tìm x biết: 30%x - x + 5/6 = 1/3

Tìm x biết; 

a) 30% . x - x + 5/6 = 1/3

b) (2x-1).(3x+12)=0

c) 3.2^2x+1 + 1/2=49/2

d) |2x-1/2|=3/4

e) (4/13 . 6/5 + 4/13 . 2/5).(2x+1)^2=10/13