[tex] \sf a)3+(-4 )-(+3)+(+9)
\\\\
\sf=>3-4-3+9\\
\sf=>-4+9\\
\sf => \red{ +5~ ou ~5}
\\ \\
\sf b) -6 - ( +3 ) + ( -5 ) + ( -3 )
\\ \\
\sf => -6 -3 -5 -3 \\
\sf => ( -6 -3 ) + ( -5 -3 ) \\
\sf => ( -9 ) + ( -8 ) \\
\sf => -9 -8 \\
\sf => \red{ -17}
\\ \\
\sf c) -6 +(-3) - 5 - 2 :
\\ \\
\sf => -6-3-5-2 \\
\sf => -9 + (-7) \\
\sf => -9 -7 \\
\sf => \red{-16}
\\ \\
\sf d) 3-(-7) + 3 + (-5) =
\\ \\
\sf => 3+7+3-5 \\
\sf => 13 -5 \\
\sf => \red{8}
\\ \\
\sf e) -2 + (-2) + 5 – 20 – (-5) =
\\ \\
\sf => -2-2+5-20+5 \\
\sf => -4+5-20+5 \\
\sf => 1 -20 +5 \\
\sf => -19 +5 \\
\sf => \red{-14} [/tex]
