Question

Calcule: 7- (-20) =
18 - (+17) =
18 + (-17) =
18 - (-17) =
0 - (+3) =

Answer 1

7 - (-20) = 7 + 20 = 27

18 - (+17) = 18 - 17 = 1

18 + (-17) = 18 - 17 = 1

18 - (-17) = 18 + 17 =  35

0 - (+3) = 0 - 3 = -3

Espero ter ajudado.

Answer 2

Regras de sinal:

" - " com " - " = "+"

" - " com "+" = " - "

" + " com " - " = " - "

" - " com " - " = " + "

a)
= 7- (-20)
= 7 + 20
= 27
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
b)
= 18 - (+17)
= 18 - 17
= 1
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
c)
= 18 + (-17)
= 18 - 17
= 1

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
d)
= 18 - (-17)
= 18 + 17
= 35

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
e)
= 0 - (+3)

= 0 - 3

= - 3

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨