Answer:
the amount of angle the hall is so prob like 5
Step-by-step explanation:
you provided insufficient details to answer
Use the distributive property to get 8x+28+6x+21 then combine 8x and 6x and also combine 28 and 21 to get 14x+49, do u need to go further or?
The vertex form:

(h,k) - the coordinates of the vertex

The coordinates of the vertex are
(-4,13).