I NEED TO WRITE AN EQUATION TO REPRESENT THE FOLLOWING FUNCTION

Question

INPUT X 1 2 3 4 5
OUTPUT Y 2 6 10 14 18

PLEASE HELP THIS IS MAKING US CRAZY

Answer 1

1 2
2 6
3 10
4 14
5 18

it looks like for every increase of 1 in the x
there is an increase of 4 in the y

so we have a relation of
y = 4x

BUT, notice if x = 1, I would get 4 , not 2 like we should

so how about
y = 4x - 2

test it for the other values.