Resposta :
a) 71-28= 43
b) 58-23+42= 35+42= 77
c) 89-83= 6
d) 100-67-27= 6
b) 58-23+42= 35+42= 77
c) 89-83= 6
d) 100-67-27= 6
A) (45 + 26) - (15 + 13)
71 - 28
= 43
B) 58 - (29 - 6) + 42
58 - 23 + 42
= 77
C) 89 - (19 + 22 + 42
89 - 83
= 6
D) 100 - (52 + 15) - 27
100 - 66 - 27
= 6
71 - 28
= 43
B) 58 - (29 - 6) + 42
58 - 23 + 42
= 77
C) 89 - (19 + 22 + 42
89 - 83
= 6
D) 100 - (52 + 15) - 27
100 - 66 - 27
= 6