Respuesta :

Answer:

22

Step-by-step explanation:

double negative is a plus sign

13--9=22

Answer: 22

Step-by-step explanation:

Here, we need to know the concept of changing signs. Under any circumstances, if there is a "-" sign outside of parenthesis, the signs inside need to be the opposite. If you are still not very clear, I can provide some examples below:

  • 1-(+1) ⇒ there is a "-" sign, so we need to convert the sign inside "+" to "-" ⇒ 1-1 ⇒ 0
  • 2-(-1) ⇒ there is a "-" sign, so we need to convert the sign inside "-" to "+" ⇒ 2+1 ⇒ 3

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Given

13 - (-9)

⇒There is a "-" sign outside

⇒We need to convert the sign inside "-" to "+"

⇒13+9

⇒22

Hope this helps!! :)

Please let me know if you have any questions