Question

1) resolva as expressões:
a) - (-2) + (+8)=

b) -30 + (+4). (-3) . (-5)

c) [81 ÷ (-9) . (+13)]

d) 5 + {3+[4.(-21÷7)]}

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Answer 1

A) -(-2)+(+8)=
2+8=
10

B)-30+(+4)*(-3)*(-5)=
-30+(+4)*15=
-30+60=
30

C)[81/(-9)*(+13)]=
[-9*(+13)]=
[-117]

D)5+{3+[4*(-21/7)]}=
5+{3+[4*(-3)]}=
5+{3+[-12]}=
5+{-9}
5-9
-4