Question

certo ou errado ?

A)10 - 10 + ( - 5) = - 5 - 7 + 7

B) -5 - (- 8) = 5 + 8

C)- 12 - 12 = - 12 - (+12)
D) -8 + 10 = + 10 - 8

Answer 1

A)
10 - 10 + ( - 5) = - 5 - 7 + 7
0 - 5 = - 5 + 0
- 5 = - 5 (V)  - CERTO
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
B)
-5 - (- 8) = 5 + 8
- 5 + 8 = 5 + 8 (F)  - ERRADO
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
C)
- 12 - 12 = - 12 - (+12)
- 24 = - 12 - 12
- 24 = - 24  (V)  - CERTO
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
D)
- 8 + 10 = + 10 - 8
 2 = 2 (V)  - CERTO

Answer 2

A) CERTO
10-10+(-5)=-5-7+7
0-5=-12+7
-5=-5
B) ERRADO
-5-(-8)=5+8
-5+8=5+8
3=13
C) CERTO
-12-12=-12-(+12)
-24=-12-12
-24=-24
D) CERTO
-8+10=+10-8
2=2