Jawabanmu

2014-01-29T20:57:23+07:00
10+(-4)-(-9)= 15
-12-(-9)-(-5)= 2
-11-(-18)+1= 8
-12+19-(-15)= 22
2014-01-29T21:03:43+07:00
10+(-4)-(-9)=10+(-4+9)=10+5=15
-12-(-9)-(-5)=-12+9+5=2
-11-(-18)+1=-11+18+1=8
-12+19-(-15)=-12+19+15=22