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 :)
Where is the question? I have no idea what I need to do to help u?
The point-slope form:

- given point
- given slope
The standard form:

<em>use distributive property</em>
<em>add
to both sides</em>
<em>subtract
from both sides</em>
<em>change the signs</em>

Make an equation.
80% = 0.8
'of' is multiplication
'what number' is 'x'
'is' is an equal sign
0.8 * x = 64
0.8x = 64
Divide 0.8 to both sides:
x = 80
(2 5/14) / (2 5/8 * 1 3/7)....turn them all into improper fractions
(33/14) / (21/8 * 10/7)
(33/14) / (105/28)...when dividing fractions, flip what u r dividing by, then multiply
33/14 * 28/105 = 132/210 reduces to 22/35 <==