Question

efetue as somas algebricas: a) -30- {12+[-4+(15+2-18)+5]-12}+40
b) (-7-2)+(-7+2)+(+7-2)+(+7+2)
c) 32- {(51-15)+[5+(3-1)]-10} +2

Answer 1

a)
=
-30-{12+[-4+(15+2-18)+5]-12}+40
= -30-{12+[-4 + (17-18)+5] -12}+40
= -30-{12+[-4 - 1 + 5] - 12} + 40
= -30-{12 + 0 - 12} + 40
= - 30 - 0 + 40
= 10

b)
= (-7-2)+(-7+2)+(+7-2)+(+7+2)
= - 9 - 5 + 5 + 9
= - 14 + 14
= 0

c)
= 32- {(51-15)+[5+(3-1)]-10} +2
= 32 - {36 + [5+2] - 10} + 2
= 33 - { 36 + 7 - 10} + 2
= 33 - {43 - 10} + 2
= 33 - 33 + 2
= 2