Step-by-step explanation:
Here, the given options are incomplete.
A. y²  = 4 x²  - 100
B. y  = -x² + 50 x - 300
C.  x =  -y² + 60 y - 400
D. x ²  =  - 6 y² + 200
The number of items sold by the company  = x
The profit ( in thousands) is represented as  = y
Now, here as we are looking for the equation representing profit (y)
So, we can disregard the equations which has terms (x)  and ( x²)  in left.
⇒The equations in the options C and D are eliminated.
Similarly, again we are looking for the equation for Profit , not (profit)².
So,we can disregard the equation which has terms (y²)  in left side.
⇒The equation in the options A is eliminated.
Hence, the needed equation representing the profit y is represented in the option B.
B. y  = -x² + 50 x - 300
