find the function rule

x -2 -1 0 1 2
y 9 4 -1 -6 -11

2 answers

(-2,9) (0, -1)

I chose two points (x,y)

first I will find the slope:

(-1 -9)/(0 - (-2)) = -10/2 = -5

use m = -5 (0, -1) -1 = b
y = -5x -1

Check a couple other points to make sure they work.
x y change in y/change in x which is slope
-2 9
****** -5
-1 4
****** -5
0 -1
****** -5
1 -6
****** -5
2 -11

hmmm, constant slope = -5
y = -5 x + b
9 = -5 (-2) + b
9 = 10 + b
b = -1
so
y = -5 x -1 answer

check at last point
-11 = -5(2) -1
-11 = -10 - 1 yes, good