how do I write a rule for this function?

Question

x: -4, 0, 2, 4
f(x): 4, 6, 7, 8

Answer 1

slope = (8-4)/(4--4) = 4/8 = 1/2
It is constant for all points
so
y = .5 x + b
8 = .5(4) + b
6 = b
so
y = .5 x + 6

check that for all points like (-4,4)
4 = (.5)(-4) + 6 ???
4 = -2 + 6
4 = 4 sure enough