49 points! explain your answer, you so much!

C  is  a linear function

Step-by-step explanation:

To be a liner function, the change in y/ change in x must be constant

m =(y2-y1)/(x2-x1)

A

The x value does not change but has 4 different y values.This would fail the vertical line test.  This is a vertical line so it is linear, but it is not a function

B (4-2)/(2-1) = 2

(8-4)/ (3-2) = 4/1

The slope changes  between the points so it is not a line

C  (6-8)/(1--1) = (-2)/(1+1) = -2/2 = -1

(4-6)/(3-1) = -2/2 = -1

(2-4) /(5-3) = -2/2 = -1

The slope is constant so it is a line

D  (-2-2)/(-2--3) = -4/(-2+3) =-4/1 = -4

  (4--2) / (-1--2) = (4+2)/(-1+2) = 6/1 = 6

The slope is not the same between these points so it is not linear

the equivalent expression are always the hardest ones but you look at the gcf also

step-by-step explanation: