Please Help urgent

g(x)=(2/3)x(x+8)

In this form the x intercepts are easy to find...these are just the roots

So (2/3) x (x - 8 ) = 0      multiply through by 3/2

x ( x - 8) = 0

x = 0     is a root = x intercept

And

x - 8 = 0

x = 8     is a root = x intercept

This is a parabola....The axis of symmetry is vertical..this is  just the average of the roots 

So...the axis of symmetry  is

x = (0 + 8) / 2  

x = 8 /2

x = 4  =  axis of symmetry