If you have the following points for X and Y what is the linear function rule?

Question

x = 4, 1

y = 2, -4

I think it is 1/2 x but I'm not sure if it is +6 or - 6

Answer 1

y = mx + b
f(x) = 4m + b = 2
f(x) = m + b = -4

4m + b = 2
-m -b = 4

3 m = 6
m = 2

4(2) + b = 2
8 + b = 2
b = -6

y = 2x - 6

Answer 2

thank you