Answer :

iGreen
For #3:

y = 1/2x, x = -18

Plug in -18 for 'x':

y = 1/2(-18)

y = -9

For #4:

y = -4x + 6, x = 1

Plug in 1 for 'x':

y = -4(1) + 6

y = -4 + 6

y = 2
1. [tex](2,3),(6,4),(8,11),(10,4)[/tex]
2. [tex](7,-13),(9,-9),(11,-5),(14,-1)[/tex]
Both relations are functions.

3. [tex]y(-18)=\dfrac{1}{2}\cdot(-18)=-9[/tex]
4. [tex]y(1)=-4\cdot1+6=-4+6=2[/tex]

5. It's easy to notice it's a linear function.
[tex]y=mx+b\\ m=\dfrac{y_2-y_1}{x_2-x_1}\\\\ m=\dfrac{-10-(-5)}{2-1}\\ m=\dfrac{-5}{1}\\ m=-5\\\\ -5=-5\cdot1+b\\ b=0\\\\ \boxed{y=-5x}[/tex]