Answer:
B) 3
Step-by-step explanation:
f(3) = 3^2 + 3(3) = 9 + 9 = 18
 
        
             
        
        
        
So to solve problems like these you can work out each equation by substituting the x and y with the coords from the vertex (2,-4) and which ever one is true is the corresponding equation.
Lets try the first one 
A) y = 2( x-2)^2-4    this would become
   -4 = 2(2-2)^2-4    we solve this and get
    -4 = 2(0)-4
    -4 = -4  
so it seems like A is the correct answer, of course we'd wanna check out the other answers just to be sure.
Lets try one and do C
C)  -2 = 2(-4-2)^2+2   
     -2 = 2(-8)^2+2
     -2 = 130
These aren't equal so this can't be our equation
So you can also do one more just to be super sure you have the right answer but I think A is the correct one :)
 
        
             
        
        
        
Answer: 
<u>Move all terms to the left</u>
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<u>Add all the numbers together, and all the variables</u>
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<u></u>
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<u>Multiply elements</u>
<u></u> <u></u>
<u></u>
<u></u>
<u>Move all terms containing d to the left, all other terms to the right</u>
<u></u> <u></u>
<u></u>