Non proportional it should be
Solution for part A is where the red line and the red line meet, (2,-1)
solution for part B: any point on the blue red line is a solution. (2, -1), (0, 3), (3, -3), (-2, 7)
solution for part C is where the green curve and the blue line meet, (0,3)
I think its the first one
$20-$14.56=$5.44
The mechanic would get $5.44 back as change.
Answer:
First, subtract 
from both sides.
Then, <em>divide</em> both sides by 4.
