The the parabola opens upward it has a minimum and if it opens downward then it has a maximum :)
Answer:

Step-by-step explanation:
From the question we are told that
February Heat
February Gas 
April Heat
April Gas 
Generally equation for heating degree-days X is mathematically given by



Generally the equation for gas bill Y is mathematically represented by

The equation representing the relationship between the gas bill (Y) and heating degree-days (X) is

Answer:
- B) 48
- D) 81
- A) 11
- B) -81
- -246
- C) 5
- A) 19 9/25
- D) 11
- A) 48
- D) m-c/-b =a
Step-by-step explanation:
comment if you want the explanation, but you said you wanted it fast and it would take me like 10 minutes to right it all out