Question 726210
As x increases by 2, y decreases by 2. So the slope is -2/2 = -1. So m = -1


The y intercept is 20 since this is where x = 0. So b = 20


This means y = mx+b turns into y = -1x + 20 which is just <font color="red">f(x) = -x+20</font> which is your final answer (in function notation).