Respostas

2014-04-10T23:25:13-03:00
A) -4 -7 = - 11
B) 6 + 12 -7 - 12= 18 -7 -12= 18 - 19 = -1
2014-04-10T23:34:55-03:00
A) -4-7= -11

B) 6+12-7-12= 18-19 = -1