Which quadratic function is best represented by this graph? f(x)=x2−6x−8

f(x)=x2+8

f(x)=x2−6x+8

f(x)=x2+6x+8
The graph of a quadratic function with a vertex at negative 3 comma negative 1 and zeros at negative 2 and negative 4

Starting at home, emily traveled uphill to the hardware store for 606060 minutes at just 666 mph. she then traveled back home along the same path downhill at a speed of 121212 mph. what is her average speed for the entire trip from home to the hardware store and back?