The explanation is on the board just tell me if you have questions
The answer would be number three because the slope is going towards the bottom of the graph
we have

Convert to vertex form

we know that
the equation of a vertical parabola in vertex form is equal to

where
(h,k) is the vertex

Group terms that contain the same variable, and move the constant to the opposite side of the equation

Complete the square. Remember to balance the equation by adding the same constants to each side


Rewrite as perfect squares


the vertex is the point 
therefore
<u>the answer is </u>
The y-value of the vertex is 