Respostas

2014-02-22T12:47:06-03:00
(+50) + (-50) = 0
-70 + 20 = -50
(+130) + (+101)  = 231
+76 - 89 = -13
0 + (+82)  = 82 
0 + (-49)  = -49
-8 + 0  = -8
+93 + 0  = 93
1 5 1
2014-02-22T12:47:39-03:00
(+50) + (-50) = 0
-70 + 20 = -50
130 + 101 = 231
+76 - 89 = -13
0 + 82 = 82
0 - 49= -49 
-8 + 0= -8
93+0= 93 :*