Jawabanmu

2014-09-03T14:18:11+07:00
1. (3-17x+35y)+(4x+23y-9)
     =-17x+4x+35y+23y+3-9
     =-13x+58y-6
2. (42n+35m+7)-(50m-20n+9)
   =42n+20n+35m-50m+7-9
   =62n+15m-2