If 9 pizzas cost $67.50 that means that 1 pizza costs 67.50/9 = $7.5
Answer A is incorrect because of false prize of pizza.
B isn't correct because 1 pizza cost $7,5 and not 7,5 pizzas cost $1
C isn't answer because of both reasons from answer A and answer B
D is the answer because it says that you need to pay $7.5 per pizza.
Answer:

Step-by-step explanation:
Given:

Required
Rewrite in vertex form
The vertex form of an equation is in form of: 
Solving: 
Subtract 2 from both sides


Factorize expression on the right hand side by dividing through by the coefficient of x²


Get a perfect square of coefficient of x; then add to both sides
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<em>Rough work</em>
The coefficient of x is 
It's square is 
Adding inside the bracket of
to give: 
To balance the equation, the same expression must be added to the other side of the equation;
Equivalent expression is: 
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The expression becomes



Factorize the expression on the right hand side





Make y the subject of formula

<em>Solved</em>
Answer:
Step-by-step explanation: