Help 3 ​

The 1st one would be the answer. 

The reason I chose the 1st one instead of the 2nd one is b/c if you see the Domain, it goes all across on both sides and covers each value. As for the range, it doesn't. 

This is a hyperbola that intercepts the y axis

Here's the graph, NSS

https://www.desmos.com/calculator/bmuwoataoe

The center  is  (0,0)

Putting this into standard form by dividing both sides by 84  we have

y^2            x^2

___    -    _____     =     1

  7              28

The domain is all real numbers because the graph  extends to infinity in both directions along the x axis

The  range  is   y ≤ - √7   and  y  ≥ √7

The first answer is correct