Posted by raquel on .
what is the rule if the input is 1 and output is 9 and input is 2 and output is 12 and the input is 3 and output 16

math,geometry 
Reiny,
1 > 9
2 > 12
3 > 16
hard to tell, it is not linear,
I don't know what level this is,
let's assume it is a quadratic
I did some quick calculations and got
y = (1/2)x^2 + (3/2)x + 7
or
y = (x^2 + 3x + 14)/2
works for your 3 values