Respostas

2013-06-03T11:56:44-03:00

a) {[(-50 -10)+11]+20}+10=

{[(-60)+11]+20}+10=

{[-49]+20}+10=

{-49+20}+10=

{-29}+10=

-29+10=

-19

 

b)18-[2+(7-3-8)-10]=

18-[2+(7-11)-10]=

18-[2+-4-10]=

18-[2-14]=

18-[-12]=

18+12=

30

 

-8+(12:3)= 

-8+6=

-2

 

 

(-15):(-3)+7=

-5+7=.

2

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