In your equation: a+(-4)=-13
you then add four to each side,
so a= negative 13 plus 4
so a= -9
Answer:

Step-by-step explanation:





Step-by-step explanation:
Here is your answer
http://www.lasesp.com/article/16336607434947849/Surprise_Gift
Answer:
a
Step-by-step explanation:
to be a function, every x has to have exactly one y, so there can't be the same number x twice wirh different y's
Answer:
-3.9/1
Step-by-step explanation: