Jawabanmu

2014-02-17T19:20:11+07:00
(z+1+z-1)/3=1
2z/3=1
2z=3
z=3/2
2014-02-17T19:44:07+07:00
(z+1)/3 + (z-1)/3 =1
2z /3 =1 
2z = 3
z = 3/2