Help I’m really confused and I don’t understand it

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

From the beginning of the day the temperature rose 15 degrees so that by 4 pm it was 87 degrees. what was the temperature at the start of the day

Madeline takes her family on a boat ride. going through york canal, she drives 6 miles in 10 minutes. later on as she crosses stover lake, she drives 30 minutes at the same average speed. which statement about the distances is true?