Question

5-Resolva as expressões abaixo:

1) 15 -(3-2) + ( 7 - 9) =                       

2) 25 - ( 1 - 5 + 3) - ( 12 - 5 - 8) = 
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Answer 1

$\boxed{\begin{array}{l}\rm 1)~\sf 15-(3-2)+(7-9)\\\sf15-(1)+(-2)\\\sf15-1-2=12\\\rm 2)~\sf25-(1-5+3)-(12-5-8)\\\sf25-(-1)-(-1)\\\sf25+1+1=27\end{array}}$

Answer 2

1. 15-(3-2)+(7-9) =
15-1+(7-9)
15-1+(-2)
15-1-2 = 12

2. 25-(1-5+3)-(12-5-8) =
25-(-1)-(12-5-8)
25-(-1)-(-1)
25+1-(-1)
25+1+1 = 27