2【4/3x-（2/3x-1/2）】=3/4x
2【4/3x-2/3x+1/2】=3/4x
2【2/3x+1/2】=3/4x
4/3x+1=3/4x
4/3x-3/4x =-1
7/12x=-1
x=-12/7