Răspuns :
a) - 3 - 8 + 12 - 4 + 11 = 8
= - 11 + 12 - 4 + 11 =
= ( - 11 + 11 ) + 12 - 4 =
= 8
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b) 4 - 5 + 11 - 9 - 4 = - 1 + 11 - 9 - 4 = 10 - 13 = - 3
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c) 9 - 2 - 8 + 4 - 21 = 7 - 4 - 21 = 3 - 21 = - 18
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d) - 16 - 7 + 32 - 21 + 17 = - 23 + 11 + 17 = - 12 + 17 = 5
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e) - 16 + 9 + 27 - 11 - 8 = - 7 + 27 - 19 = 20 - 19 = 1