The vertex form of the equation of a parabola is y = 3(x - 4)2 - 22.
What is the standard form of the equation?

Will medal!

Question

The vertex form of the equation of a parabola is y = 3(x - 4)2 - 22.
What is the standard form of the equation?

Will medal!

anonymous · Answer

A. 	y = 3x2 - 24x + 26
  		B. 	y = 9x2 - 26
  		C. 	y = 3x2 - 24x + 4
  		D. 	y = 3x2 - 18

^ these are the answer choices. :)

ddcamp · Answer

The standard form is
$$y = ax^2 + bx + c$$

To figure out which of the answers is correct, let's start by expanding the (x-4)² term.

ddcamp · Answer

What's
$$3*(x-4)*(x-4)?$$

anonymous · Answer

I know that x-4 expanded is 8x. 
8x times 3 = 24x :3

ddcamp · Answer

How did you get 8x from (x-4)*(x-4)?

anonymous · Answer

I multiplied the two 4x's. It's a bit of a shortcut, but it helps. :p

ddcamp · Answer

I don't think that shortcut helps here.
Let's try the good ol' FOIL method:
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