It's an upside (-) down parabola. The axis of symmetry is the x coordinate of the vertex.
you can easily find this using formula: x= -b/2a
for parabola: ax² + b + c = 0
x = -16 ÷ 2(-4)
x = 2
Answer C
It takes 8 hours to drive to Joliet, and that's 6 hours more than half the time it takes to drive to Davenport. So, I did 8-6 which equals 2. So 2 hours is half the time it takes to get to Davenport, which means it takes 4 hours to get to Davenport.
