Jawabanmu

2014-01-27T20:03:50+07:00
3z + 11 = -28
3z = -28 - 11
3z = - 39
z = -39/3
z = -13
2014-01-27T20:05:25+07:00
3z+11    =-28
3z+11-11=-28-11
3z         =-39
1/3(3z)   =1/3(-39)
    z       =-13