Supply is the amount of product a seller is able to make
12 - 2x = -2(y - x)
12 - 2x = -2y - (-2x)
12 - 2x = -2y + 2x
12 - 2x - 2x = -2y + 2x - 2x
12 - 4x = -2y
12 - 12 - 4x = -2y - 12
-4x = -2y - 12
-4x/4 = -2y/4 - 12/4
-x = -0.5y - 3
-x/-1 = -0.5y/-1 - 3/-1
x = 0.5y + 3
or
x = 3 + 0.5y
Answer:
C. 
Step-by-step explanation:
You can solve this in two ways, firstly by eliminating all the wrong answers, and secondly by just knowing that the horizontal line in 
means that we are talking about a line.
This is how we solve this question by using the eliminating process.
(A. ∠C) is not the right answer because the ∠ sign lets us know that this answer represents an angle, not a line
(B. <em>B) </em>is not the right answer because it represent a point, not a line (in math we use a singular capital letter to represent points)
(D. ΔABC) is not the right answer because the Δ sign lets us know that the answer represents a triangle, not a line.
Therefore, the only option left is C. 