Question

2)elimine parenteses colchetes e chaves e efetue a soma algebrica: a)12-(-4+5)
b)-20+(+4-6)
c)8+(-20+3)
d)5-(+5)-(-15+5)
e)-5+[(+8-12)-(-9)]
f)2-[(-4+8)+(-6+3)]
g)5-[-4-(+9+3+5)]
h)-6+{-3+[2-(-4+3)]}
i)9-{-4+[3-(+7-3)]}
j)6-{-8-[-5+(-2+1)]}
m)-(-2+6)+[2-(8+1)]
h)(5-1)-{-[-(-6+5-2)]}

Answer 1

a) 12 - (+1) => 12 - 1 => 11
b) -20 +4 - 6 => -22
c) 8 + ( -17) => 8 - 17 => - 9
d)5 - 5 +15 -5 => 10
e) - 5 + [ - 4 +9 ] => - 5 +1 => 6
f) 2 - [ - 4 + 8 - 6 +3 ] => 2 +4 -8+6-3 => 1
g) 5 - [ -4 -17] => 5 +21 => 26
h) -6 + { -3 + [ 2 + 1]} => -6 + { -3 + 3} => -6 + 0 => -6
i) 9 -{-4+[3-4]} => 9-{-4-1} => 9 + 5 => 14
j) 6 - { -8-[ -5-1]} => 6 -{-8+6} => 6 +2 = 8
m) -4+[2-9] => -4 - 7 => -11
n) 4-{-[+3]} = 4 - { -3} => 4 + 3 => 7

Answer 2

a) 12-(-4+5) -> 12-(1) -> 12 - 1 = 11
b) -20+(4-6) -> -20+(-2) -> -20-2 = -22
c) 8+(-20+3) -> 8+(-17) -> 8-17 = -9 
d) 5-(+5)-(-15+5) -> 5-5+10 = 10
e) -5+[(8-12)-(-9)] -> -5+[-4+9] -> -5+5 = 0
f) 2-[(-4+8)+(-6+3)] -> 2-[4-3] -> 2-1 = 1
g) 5-[-4-(9+3+5)] -> 5-[-4-17] -> 5-[-21] -> 5+21 = 26
h) -6+{-3+[2-(-4+3)]} -> -6+{-3+[2+1]} -> -6+{-3+3} -> -6+0 = -6
i) 9-{-4+[3-(7-3)]} -> 9-{-4+[3-4]} -> 9-{-4-1} -> 9+5 = 14
j) 6-{-8-[-5+(-2+1)]} -> 6-{-8-[-5-1]} -> 6-{-8+6} -> 6+2 = 8
m) -(-2+6)+[2-(8+1)] -> -4+[2-9] -> -4-7 = -11
n) (5-1)-{-[-(-6+5-2)]} -> 4-{-[3]} -> 4-{-3} -> 4+3 = 7

espero ter ajudado :)