Explain how to write a function rule from the table below. Then write a function rule.

x 2 4 6
y 1 0 –1

1 answer

y = mx + b
f(x) = 2m + b = 1
f(x) = 4m + b = 0
f(x) = 6m + b = -1

-1(2m + b = 1)
4m + b = 0

-2m -b = -1
4m + b = 0

2m = -1
m = -1/2
2(-1/2) + b = 1
-1 + b = 1
-1+ 1 + b = 1 + 1
b = 2
y = mx +b
y = -1/2x + 2