what is the rule for the function shown in the table below?

x -1 0 1 2

y -2 1 4 7

1 answer

note that as x increases by 1, y increases by 3, so first guess:

y = 3x

But, y(0) = 1 instead of 0, so next guess:

y = 3x+1

that works for all of them.