Answer:
x+9
Step-by-step explanation:
the sum is the answer to an addition question
"a number" is a variable (I chose x, but it can be pretty much anything you'd like :)
so, the sum of a number and 9 would be x+9 because you are adding "a number" and 9
12 and 3 because 3 divided by 12=4 and 12x3=36
Answer:
neither
Step-by-step explanation:
if you put those coordinates on a graph it would be curved and not be linear
